Abstract: An antenna includes a reference ground and at least a radiating source spacedly disposed at the reference ground to define a radiating clearance between the radiating source and the reference ground, wherein the radiating source is electrically connected to the reference ground to ground the radiating source so as to narrow a bandwidth of the antenna. When a electromagnetic excitation signal is received at a feed point of the radiating source, the bandwidth of the antenna is narrowed down to prevent any interference of the electromagnetic wave signal received or generated by the antenna in response to nearby electromagnetic radiation frequency or stray radiation frequency of the adjacent frequency bands.

Abstract: An anti-interference microwave antenna includes a reference ground and at least a radiating source spacedly disposed at the reference ground to define a radiating clearance between the radiating source and the reference ground, wherein the radiating source is electrically connected to the reference ground to ground the radiating source so as to narrow a bandwidth of the antenna. When a electromagnetic excitation signal is received at a feed point of the radiating source, the bandwidth of the antenna is narrowed down to prevent any interference of the electromagnetic wave signal received or generated by the antenna in response to nearby electromagnetic radiation frequency or stray radiation frequency of the adjacent frequency bands.

Abstract: A terrestrial receiver at a premises includes a plurality of antennas and a corresponding plurality of tuners. The terrestrial receiver receives terrestrial television signals via the plurality of antennas and the plurality of tuners and diversity combines a corresponding plurality of terrestrial television channels within the received terrestrial television signals, for example, based on control signals received from one or more customer premises equipment (CPE). The terrestrial receiver processes the diversity combined corresponding plurality of terrestrial television channels and communicates the processed and diversity combined corresponding plurality of terrestrial television channels to the one or more CPE. The diversity combined corresponding plurality of terrestrial television channels may be remodulated, and converted to corresponding analog signals prior to being communicated to the one or more CPE.

Abstract: An anti-interference microwave antenna includes a reference ground and at least a radiating source spacedly disposed at the reference ground to define a radiating clearance between the radiating source and the reference ground, wherein the radiating source is electrically connected to the reference ground to ground the radiating source so as to narrow a bandwidth of the antenna. When a electromagnetic excitation signal is received at a feed point of the radiating source, the bandwidth of the antenna is narrowed down to prevent any interference of the electromagnetic wave signal received or generated by the antenna in response to nearby electromagnetic radiation frequency or stray radiation frequency of the adjacent frequency bands.

Abstract: An arrangement for detection of multiple signals concurrently is disclosed. The arrangement includes a demodulator component, a mixer and a detector. The demodulator component is configured to demodulate or obtain one or more components from a received signal. The mixer is configured to mix the one or more components into a folded signal using a plurality of varied local oscillator (LO) signals. The detector is configured to identify a valid signal within the folded signal and to initiate a response for the identified valid signal.

Abstract: Carrier aggregation systems and methods are disclosed. In some embodiments, a radio-frequency circuit can include a first signal path configured to present an approximately zero impedance to a first out-of-band signal that is out of a first frequency band. The radio-frequency circuit can further include a coupling circuit coupled to the first signal path and configured such that the approximately zero impedance presented by the first signal path to the first out-of-band signal results in the first out-of-band signal being substantially excluded from the first signal path. The radio-frequency circuit can further include a second signal path configured to present an approximately zero impedance to a second out-of-band signal that is out of a second frequency band.

Abstract: Apparatus comprises adapter and speaker system. Adapter is configured to plug into port of personal digital audio player. Speaker system is in communication with adapter, and comprises multiple acoustic transducers, programmable processor circuit, and wireless communication circuit. In first operational mode, processor circuit receives, via adapter, and processes digital audio content from personal digital audio player into which adapter is plugged, and the multiple acoustic transducers output the received audio content from the personal digital audio player. In second operational mode, wireless communication circuit receives digital audio content from a remote digital audio source over a wireless network, processor circuit processes the digital audio content received from remote digital audio source, and the multiple acoustic transducers output the audio content received from the remote digital audio source.

Abstract: An ultrasound receiving method is provided. N return-wave signals corresponding to N channels are respectively stored in N set of shift register arrays. Each set includes a delay filter unit and M shift registers. A delay controller is utilized to assign a set of coefficients to the delay filter unit to perform an interpolation operation on data of the M shift registers to obtain an output value. The delay controller is utilized to decide delay time of each channel according to a delay table, and accordingly to control a time multiplexer to switch and output the N output values in order. A multiplier is utilized to multiply the output value received from the time multiplexer by a weighted value corresponding to the channel to obtain a corrected value. An accumulator is utilized to accumulate the N corrected values to obtain an image value.

Abstract: Methods and apparatuses are provided for dynamic frequency scaling of an intermediate frequency (IF) signal within a radio device.

Abstract: A system may comprise a plurality of signal processing paths, a bin-wise combiner, an inverse transformation block, and a DAC. Each signal processing path may comprise a transformation block that is operable to transform a first time-domain digital signal to an associated frequency-domain signal having a plurality of subband signals. The bin-wise combiner may be operable to combine corresponding subband signals of the plurality of signal processing paths. The inverse transformation block may be operable to transform output of the bin-wise combiner to an second time-domain signal. The DAC may be operable to converts the second time-domain signal to a corresponding analog signal.

Abstract: A unidirectional sampling mixer utilizes a stepped phase modulation to shift the frequency of an input signal. An RF input signal is supplied to an RF input switch from an RF input port. An ordered set of phase shift values to be applied to the RF input signal and a set of times each element of which correspond to a time at which a phase shift value is be applied to the RF signal are determined. For each phase shift value within the ordered set of phase shift values, a controller controls the RF input switch to select an input of a phase shifting device and controls an RF output switch to select an output of the phasing shifting device. The input of the phase shifting device and the output of the phase shifting device are selected to apply the phase shift value at its corresponding time to the RF input signal. A frequency shifted signal is supplied to an RF output port from an output of the RF output switch.

Abstract: Various embodiments implement apparatuses and methods for conversion of radio frequency (RF) signals to intermediate frequency (IF) signals. More particularly, some embodiments are directed toward down conversion of RF signals to IF signals in a multi-band radio receiver, such as a satellite receiver, using a single oscillator for different frequency bands. For example, some of the apparatuses and methods presented are suitable for integration into monolithic RF integrated circuits in low-cost satellite receivers for home entertainment use.

Abstract: The invention provides an adaptive harmonic rejection (HR) receiving device, including a low noise amplification module; at least one HR mixer; at least one non-harmonic rejection (NHR) frequency mixer; and a control device. A received signal passes through the low noise amplification, and then passes through the at least one HR mixer or the at least one NHR mixer; the control device measures a receiving signal strength index (RSSI) after the received signal passes through the at least one HR mixer or the NHR mixer, and selects an NHR mixer or an appropriate HR mixer for the received signal according to a result of the measurement. The adaptive HR receiving device of the present invention is capable of adaptively judging whether to implement HR or determining which HR to implement according to features of the received signal, thereby improving the reception flexibility and reception performance.

Abstract: A wireless receiver designed to conform to the standard IEEE 802.15.4. The receiver comprises an analog front-end and a digital decoder. The analog components of the front end include one or more amplifiers and an analog-to-digital converter (ADC). The digital decoder receives the output of the ADC and demodulates it in a demodulator which is driven at an a chip frequency by an internal or external clock. The demodulator comprises a sampler operable to sample the digital signal at a sampling frequency and a correlation unit operable to process a set of bits, referred to as a chip code, in the sampled digitized signal and output therefrom a set of correlation values. The set of correlation values is an indicator of likely mapping between the chip code that has been processed and a set of possible chip codes defined according to the standard. The demodulator further comprises a symbol selection unit and a frequency correction unit.

Abstract: A multichannel radio receiver is configured to define at least two channel plans, each channel plan having at least one channel. The channel plans may differ due to channel bandwidths, channel locations, channel number and/or channel spacings. At least a portion of a radio spectrum may be common to at least two of the channel plans. At least two decoders may operate simultaneously to decode different modulation schemes on each of the at least two channel plans. In one example, two channel plans overlap portions of the radio spectrum. Two different and complementary modulation schemes are used on the two channel plans, respectively. The complementary modulation schemes reject signals associated with the other. Accordingly, portions of the radio spectrum are used simultaneously by at least two channel plans and at least two modulation schemes, respectively.

Abstract: The noise response in a passive mixer circuit is improved by discharging the switching transistors in the mixer circuit in an appropriate time slot prior to activation. In addition to improving the noise response, tilt in conversion gains and linearity can be reduced. A passive mixer circuit includes bypass switches arranged in proximity to the switching transistors that make up the mixer core. These bypass switches, which are activated in intervals just prior to the active intervals of their neighboring switching transistors, discharge to ground accumulated charges on the switching transistors or on reactive components around switches.

Abstract: A unidirectional sampling mixer utilizes a stepped phase modulation to shift the frequency of an RF input signal supplied to an RF input switch. An ordered set of phase shift values to be applied to the RF input signal and a set of times each element of which corresponds to a time at which a phase shift value is be applied to the RF signal are determined. For each phase shift value, a controller controls the RF input switch to select an input of a phase shifting device and controls an RF output switch to select an output of the phasing shifting device. The input and the output of the phase shifting device are selected to apply the phase shift value at its corresponding time to the RF input signal. A frequency shifted signal is supplied to an RF output port from an output of the RF output switch.

Abstract: A radio receiver including a sampling unit, a provider, an arithmetic operation unit, an estimator, and a converter. The sampling unit samples a baseband signal transmitted from the radio transmitter, at a fractional multiple of a symbol rate, and generates fractional-multiple-sampling data. The provider provides reference data in which the known symbol sequence arranged in a frame by the radio transmitter is interpolated at a rate of the fractional multiple. The arithmetic operation unit performs an arithmetic operation for evaluation data in which the degree of consistency in waveform between the fractional-multiple-sampling data and the reference data is evaluated. The estimator estimates a reference timing from a shift amount at which the evaluation data shows the maximum degree of consistency in waveform. The converter converts the fractional-multiple-sampling data by using the reference timing as a reference thereby recovering the data having the symbol rate.

Abstract: A receiver may comprise a plurality of signal processing paths, a bin-wise combiner, and an inverse transformation block. Each signal processing path may comprise a transformation block that is operable to transform a time-domain digital signal to an associated frequency-domain signal having a plurality of subband signals. The bin-wise combiner may be operable to combine corresponding subband signals of the plurality of signal processing paths. The inverse transformation block may be operable to transform output of the bin-wise combiner to an associated time-domain signal. The transformation block in each said signal processing path may be a Fast Fourier Transform (FFT) block. The number of points used by the FFT block of any one of said plurality of signal processing paths may be based on the delay spread of a signal input to the one of the signal processing paths.

Abstract: Certain aspects of a method and system for mitigating effects of pulling in multiple phase locked loops in multi-standard systems may include selecting an input frequency range of operation at a voltage controlled oscillator based on a particular wireless band of operation in a system that handles a first wireless communication protocol and a second wireless communication protocol. An image rejection mixer may be enabled to generate an output signal for the particular wireless band of operation based on mixing a plurality of received signals within a selected frequency range. An in-phase (I) component and a quadrature (Q) component of the generated output signal may be generated by utilizing a RC-CR quadrature network.

Abstract: A system may comprise a plurality of signal processing paths, a bin-wise combiner, an inverse transformation block, and a DAC. Each signal processing path may comprise a transformation block that is operable to transform a first time-domain digital signal to an associated frequency-domain signal having a plurality of subband signals. The bin-wise combiner may be operable to combine corresponding subband signals of the plurality of signal processing paths. The inverse transformation block may be operable to transform output of the bin-wise combiner to an second time-domain signal. The DAC may be operable to converts the second time-domain signal to a corresponding analog signal.

Abstract: A wideband receiver system is provided to concurrently receive multiple RF channels including a number of desired channels that are located in non-contiguous portions of a radio frequency spectrum and to group the number of desired channels into a contiguous frequency band. The system includes a wideband receiver having a complex mixer for down-shifting the multiple RF channels and transforming them to an in-phase signal and a quadrature signal in the baseband. The system further includes a wideband analog-to-digital converter module that digitizes the in-phase and quadrature signals and a digital frontend module that transforms the digital in-phase and quadrature signals to baseband signals that contains only the number of desired RF channels. that are now located in a contiguous frequency band. An up-converter module up-shifts the baseband signals to a contiguous band in an IF spectrum so that the system can directly interface with commercially available demodulators.

Abstract: A television broadcast receiving apparatus can change an oscillation frequency of a local oscillation signal or a tuning frequency of an intermediate frequency signal in a reception channel, and changes the reception characteristic to an optimum reception characteristic. In this way, the television broadcast receiving apparatus effectively reduces SN ratio deterioration due to interference of the outside of a reception band such as adjacent channel interference.

Abstract: A down-conversion module for a heterodyne receiver comprises a first mixer circuit, a second mixer circuit and an interconnection. The first mixer circuit includes first and second differential control terminals and is arranged to produce a first down-converted differential voltage signal at a first down-converted frequency as a function of a first RF differential input signal applied to the first differential control terminals and of a first RF differential reference frequency signal applied to the second differential control terminals.

Abstract: A radio frequency (RF) receiver comprises an analog receiver, a digital processor, a clock synthesizer, and a microcontroller. The analog receiver has an input for receiving an RF input signal, and an output for providing a digital intermediate frequency (IF) signal. The digital signal processor has a first input for receiving the digital IF signal, a second input for receiving a clock signal, and a signal output for providing an IF output signal. The clock synthesizer has an input for receiving a clock control signal, and an output for providing the clock signal. The a microcontroller has an input for receiving a channel selection signal, wherein the microcontroller provides the clock control signal to control a frequency of the clock signal dynamically in response to a channel selection input to reduce interference of sub-harmonics created by the clock signal on the analog receiver.

Abstract: A discrete time receiver includes a low noise transconductance amplifier (LNTA), a discrete time sampler, a passive discrete time circuit, and a switched capacitor amplifier. The LNTA amplifies a received RF signal and provides an amplified RF signal. The discrete time sampler samples the amplified RF signal (e.g., with multiple phases of a sampling clock) and provides first analog samples. The passive discrete time circuit decimates and filters the first analog samples and provides second analog samples. The switched capacitor amplifier amplifies the second analog samples and provides third analog samples. The discrete time receiver may further include a second passive discrete time circuit, a second switched capacitor amplifier, and an analog-to-digital converter (ADC) that digitizes baseband analog samples and provides digital samples. The discrete time receiver can flexibly support different system bandwidths and center frequencies.

Abstract: A method for signal processing includes distributing an analog input signal to a plurality of processing channels. In each processing channel, the input signal is mixed with a respective periodic waveform including multiple spectral lines, so as to produce a respective baseband signal in which multiple spectral slices of the input signal are superimposed on one another. The baseband signal produced in each of the processing channels is digitized, to produce a set of digital sample sequences that represent the input signal.

Abstract: A plurality of carrier signals in a wide band signal is converted into a plurality of digital carrier signals. Each of the plurality of carrier signals is at a respective frequency in the wide band signal. At least one of the plurality of digital carrier signals is translated to a different frequency.

Abstract: Methods may be provided to simultaneously receive first and second RF (radio frequency) carriers over respective first and second RF carrier frequencies. More particularly, the first and second RF carriers may be provided at an RF mixer stage. During a first time period, the first and second RF carriers may be down converted through the RF mixer stage using a first RF mixer frequency to generate first downconverted signals, and the first downconverted signals may be processed to provide first and second DC carriers corresponding to the first and second RF earners. During a second time period, the first and second RF carriers may be downconverted through the RF mixer stage using a second RF mixer frequency to generate second downconverted signals with the first and second RF mixer frequencies being different, and the second downconverted signals may be processed to provide the first and second DC carriers corresponding to the first and second RF carriers. Related devices are also discussed.

Abstract: A communication apparatus includes transmission circuitry and a frequency conversion unit. The transmission circuitry is configured to down-convert an input Intermediate Frequency (IF) signal using a transmit (TX) Local Oscillator (LO) signal so as to produce a TX baseband signal, to up-convert the TX baseband signal to produce an output Radio Frequency (RF) signal, and to send the output RF signal to an antenna. The frequency correction unit is configured to estimate a frequency of the TX baseband signal or of the input IF signal, and to adjust the TX LO signal based on the estimated frequency so as to cause the transmission circuitry to down-convert the input IF signal to a predefined target frequency.

Abstract: A device for double frequency transposition includes means for controlling the frequencies FOL1, FOL2 of a first and a second synthesizer, which are adapted to carry out the steps of (a) initializing the frequency FOL2 at a first given value FOL2,A; and (b) for a given pair of frequencies FRF, FFI2, determining the frequency FOL1 with the aid of the following relations: if FRF>FOL1 and FFI1<FOL2, FRF=FOL1+FOL2?FFI2??(5), if FRF>FOL1 and FFI1>FOL2, FRF=FOL1+FOL2+FFI2??(6), if FRF<FOL1 and FFI1>FOL2, FRF=FOL1?FOL2?FFI2??(7), if FRF<FOL1 and FFI1<FOL2, FRF=FOL1?FOL2+FFI2??(8); and (c) if the value obtained for FOL1 lies in a frequency band of lower bound A·FREF?B·X and upper bound A·FREF+B·X, where A is a strictly positive integer and X is a given parameter, modifying the frequency FOL2 to a second value FOL2,B determined so that the difference in absolute value between FOL2,A and FOL2,B satisfies the following two conditions: |FOL2,B?FOL2,A|>AFREF+2B·X |FOL2,B?FOL2,A|<AFREF

Abstract: A signal processing apparatus includes: a digital processing unit to which a digital input signal is supplied, which performs a digital process on the digital input signal to produce a digital signal, and which produces a control signal designating a specific time period when an amplitude of an analog output signal is to be lowered; a DA-conversion unit which converts the digital signal to produce an analog signal; and a variable gain unit which adjusts an amplitude of the analog signal to produce the analog output signal, and which lowers the amplitude of the analog output signal during the specific time period designated by the control signal.

Abstract: A radio receiver including a sampling unit, a provider, an arithmetic operation unit, an estimator, and a converter. The sampling unit samples a baseband signal transmitted from the radio transmitter, at a fractional multiple of a symbol rate, and generates fractional-multiple-sampling data. The provider provides reference data in which the known symbol sequence arranged in a frame by the radio transmitter is interpolated at a rate of the fractional multiple. The arithmetic operation unit performs an arithmetic operation for evaluation data in which the degree of consistency in waveform between the fractional-multiple-sampling data and the reference data is evaluated. The estimator estimates a reference timing from a shift amount at which the evaluation data shows the maximum degree of consistency in waveform. The converter converts the fractional-multiple-sampling data by using the reference timing as a reference thereby recovering the data having the symbol rate.

Abstract: Provision of gigabit-rate data transmission over wireless radio links, using carrier frequencies in the millimeter-wave range (>30 GHz). More specifically, a circuit for detection of amplitude-shift keyed (ASK) or other amplitude modulations (AM) which can be easily incorporated into an integrated circuit receiver system is described, making the receiver capable of supporting both complex IQ modulation schemes and simpler, non-coherent on-off or multiple-level keying signals. Several novel radio architectures are also described which, with the addition of a frequency discriminator network, have the capability of handling frequency shift keyed (FSK) or other frequency modulations (FM), as well as AM and complex IQ modulation schemes. These radio architectures support this wide variety of modulations by efficiently sharing detector hardware components.

Abstract: Provision of gigabit-rate data transmission over wireless radio links, using carrier frequencies in the millimeter-wave range (>30 GHz). More specifically, a circuit for detection of amplitude-shift keyed (ASK) or other amplitude modulations (AM) which can be easily incorporated into an integrated circuit receiver system is described, making the receiver capable of supporting both complex IQ modulation schemes and simpler, non-coherent on-off or multiple-level keying signals. Several novel radio architectures are also described which, with the addition of a frequency discriminator network, have the capability of handling frequency shift keyed (FSK) or other frequency modulations (FM), as well as AM and complex IQ modulation schemes. These radio architectures support this wide variety of modulations by efficiently sharing detector hardware components.

Abstract: This invention is primarily a circuit structure of self-mixing receiver, and the methodology of circuit structure is described as follows. The first stage is a high input impedance voltage amplifier utilized to amplify the received RF carrier signal from the antenna. Besides, there are no any inductors required. The second stage is a multi-stage amplifier to amplify the output signal of first stage to rail-to-rail level, which is quite the same with supply voltage. The third stage is a mixer adopted to lower the signal frequency. The fourth stage is a digital output converter, which is proposed to demodulate the electric signals and convert the demodulated signal to digital signal.

Abstract: A receiver may comprise a plurality of signal processing paths, a bin-wise combiner, and an inverse transformation block. Each signal processing path may comprise a transformation block that is operable to transform a time-domain digital signal to an associated frequency-domain signal having a plurality of subband signals. The bin-wise combiner may be operable to combine corresponding subband signals of the plurality of signal processing paths. The inverse transformation block may be operable to transform output of the bin-wise combiner to an associated time-domain signal. The transformation block in each said signal processing path may be a Fast Fourier Transform (FFT) block. The number of points used by the FFT block of any one of said plurality of signal processing paths may be based on the delay spread of a signal input to the one of the signal processing paths.

Abstract: The transmitter of the transceiver includes: a transmitter-side mixers of a transmitter-side modulator; a transmitter-side voltage-controlled oscillator; and a transmitter-side divider. The divider having a dividing factor of a non-integral number is supplied with an oscillating output of the oscillator. A pair of non-quadrature local signals having a phase difference of 90° plus a predetermined offset angle is produced by the divider and supplied to the mixers. The transmitter includes a phase-shift unit which converts a pair of quadrature transmit signals having a phase difference of about 90° on an analog basis into a pair of non-quadrature shifted transmit signals. Consequently, quadrature modulation is performed by the mixers. Use of a similar configuration enables the reduction in interference of an RF signal with local signals supplied to receiver-side mixers of the receiver.

Abstract: Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

Abstract: A system and method is provided for establishing a call to a wireless directory number which is either a non-geographic directory number or a non-dialable directory number. A call is initiated from a wireline telephone to a geographic-based local access directory number. A signaling node associated with the dialed local access DN sends a location request that includes the local access DN to an HLR. The HLR obtains the wireless DN from an internal database in which the wireless DN is associated with the local access DN. The HLR utilizes the wireless DN to receive a temporary local directory number (TLDN) from visitor location register, associates the TLDN with the local access DN and forwards the TLDN to the signaling node, which relays the TLDN to the originating switching node. The call connection is then established directly from the originating switching node to a visited cellular switch using the TLDN.

Abstract: For creating a route plan for a group of agricultural working machine systems for working a territory, the machine systems include route planning data determination devices and they exchange data with each other and, based on exchanged route planning data, one shared route plan is created for the particular territory. For controlling a group of agricultural working machine systems while it works a territory, one shared route plan—which has been created accordingly—is used, and a route planning system is provided for creating a route plan for a group of agricultural working machine systems to be used to work a territory.

Abstract: A system includes at least a first array connected to a second array. The first array includes an odd number, greater than one, of unidirectionally-coupled non-linear first array elements. The second array includes an odd number, greater than one, of unidirectionally-coupled non-linear second array elements. The second array elements are unidirectionally-coupled in a direction opposite the coupling direction of the second array elements. The first array is configured to receive an input signal and down-convert the input signal. The second array is configured to receive the down-converted input signal, further down-convert the down-converted input signal, and output a down-converted output signal. The down-converted output signal is down-converted to a multiple of the frequency of the input signal proportional to the number of arrays of the system. The system may operate at frequencies greater than 1 GHz and may be contained in a microchip or on a printed circuit board.

Abstract: A receiving apparatus includes: a frequency conversion portion that has at least a mixer that down-converts a frequency of a reception radio-frequency signal by mixing the radio-frequency signal and an output from a voltage-controlled oscillator and outputs the down-converted radio-frequency signal; and a resistor element that has a resistance value to set a DC bias voltage of an input transistor in the mixer to which the radio-frequency signal is inputted to a center value of a dynamic range.

Abstract: An apparatus and method for demodulating an FM RF signal is presented. An Adaptive Differentiate Cross Multiply (ADCM) system in which the energy estimate of the desired on-channel RF is generated using adaptive filtering. The adaptive filter includes low pass filtering of the instantaneous energy estimate. The bandwidth of the LPF is adjusted in real time based on the received signal strength energy estimate, the periodicity of any changes in the energy estimate, AGC setting for the receiver, and/or the type of sub-audible signaling applied to the RF signal if known. After the bandwidth is set, the optimum filtered energy estimate is applied to the system to demodulate the received information free from distortion artifacts associated with IQ imbalance. A normalized signal in the ADCM system is clipped by a limiter whose clipping threshold is equal to a maximum gain of differentiators in the ADCM system.

Abstract: The signal to noise ratio performance of a RF communication system can be improved by providing resistance to transmitter self-jamming and eliminating or reducing the need for a transmit rejection filter or other measures such as limiters or blanking switches. An anti-jam low noise amplifier provides enough rejection and jamming immunity to reduce or eliminate the need for the transmit reject filter. Thus, the system noise performance is improved by eliminating the filter and the associated losses which cause signal to noise ratio performance degradation.

Abstract: A wireless diversity receiver includes, in part, N signal processing paths, a bin-wise combiner, and an inverse transformation module. Each signal processing path includes, in part, a mixer adapted to downconvert a frequency of an RF signal received by that path, an analog-to-digital converter adapted to convert the downconverted signal from an analog signal to a digital signal, and a transformation block adapted to transform the digital signal represented in time domain to an associated frequency domain signal having M subband signals. The bin-wise combiner is configured to combine the corresponding subband signals of the N paths. The inverse transformation block is configured to transform the output of the bin-wise combiner to an associated time-domain signal.

Abstract: A frequency demodulator comprises a frequency discriminator configured to generate a frequency modulation signal from frequency modulated signal, circuitry for generating a phase modulation signal from the frequency modulation signal, and a click reduction signal processing (CRSP) circuit operable to remove noise enhancements from the phase modulation signal caused by clicks. By first converting the frequency modulation signal to a phase modulation signal, noise enhancements caused by clicks are more readily distinguished from other noise in the phase modulation signal. After the noise enhancements have been removed by the CRSP, the frequency modulation is recovered substantially free of clicks. Removal of the clicks results in an improved output signal-to-noise ratio, thereby advantageously extending the onset of the threshold effect.

Abstract: A wideband receiver system is provided to concurrently receive multiple RF channels including a number of desired channels that are located in non-contiguous portions of a radio frequency spectrum and to group the number of desired channels into a contiguous frequency band. The system includes a wideband receiver having a complex mixer for down-shifting the multiple RF channels and transforming them to an in-phase signal and a quadrature signal in the baseband. The system further includes a wideband analog-to-digital converter module that digitizes the in-phase and quadrature signals and a digital frontend module that transforms the digital in-phase and quadrature signals to baseband signals that contains only the number of desired RF channels. that are now located in a contiguous frequency band. An up-converter module up-shifts the baseband signals to a contiguous band in an IF spectrum so that the system can directly interface with commercially available demodulators.

Abstract: An RFIC includes a transmit acoustic transducer, a digital conversion module, a transmit baseband module, an analog conversion module, an up-conversion module, a power amplifier circuit, a low noise amplifier circuit, a down-conversion module, a receive baseband processing module, and a receive acoustic transducer circuit. The transmit acoustic transducer circuit converts transmit sound waves into transmit electrical signals. The digital conversion module converts the transmit electrical signals into digital transmit audio signals and converts down-converted signals into digital receive baseband or low IF signals. The transmit baseband processing module converts the digital transmit audio signals into digital transmit baseband or low IF signals. The analog conversion module converts the digital transmit baseband or low IF signals into analog transmit baseband or low IF signals and converts digital receive audio signals into receive electrical signals.

Abstract: A receiver includes a front end, an up-converter and an interface. The front end is configured to down-convert a first Radio Frequency (RF) signal at a first frequency, so as to produce a second signal at a second frequency, lower than the first frequency. The up-converter is configured to up-convert the second signal to produce a third Intermediate Frequency (IF) signal at a third frequency, higher than the second frequency. The interface is configured to transmit the third signal over a cable for remote demodulation.