Abstract: A bit error rate of the reception signal is detected on the reception side, such that an n optimal modulation method and LO output power are determined in accordance with this bit error rate, and an LO output changing instruction is sent to an image signal rejection mixer on the transmission side. The image signal rejection mixer changes the phase X=?+? in response to the LO output changing instruction when power splitter (201) splits the LO into two components with equal amplitude and phase difference ?, power splitter (202) splits the IF signal into two components with equal amplitude and phase difference ?, and power combiner (205) combines RF signals with equal amplitude and phase difference ?. By changing the X, the LO output power is controlled and the back-off amount of a transmission amplifier is changed in accordance with an optimal modulation scheme. In this event, ???+?=2n? (n is an integer) is set so as to maximize the image signal rejection amount.

Abstract: In an image rejection mixer, when a signal in the first radio frequency band is inputted to an input terminal, the first mixer and the second mixer convert the input signal in the first radio frequency band to a signal in the first intermediate frequency band by using the first local signal from a local signal oscillator, and a filter circuit attenuates an image interfering signal existing in the first intermediate frequency band by means of the first attenuation band. Also, when a signal in the second radio frequency band is inputted to the input terminal, the first mixer and the second mixer convert the input signal in the second radio frequency band to a signal in the second intermediate frequency band by using the second local signal from the local signal oscillator, and the filter circuit attenuates an image interfering signal existing in the second intermediate frequency band by means of the second attenuation band that is narrower than the first attenuation band.

Abstract: A receiver includes a first oscillator supplying a reference frequency signal; a reference signal generator producing a first frequency conversion signal and a local calibration signal from the reference frequency signal; a first frequency converter responsive to the first frequency conversion signal to down-convert the received signal during normal receive operation and to down-convert the local calibration signal during calibration processing; a second frequency converter responsive to a second frequency conversion signal from a second oscillator to further down-convert the received signal and the local calibration signal; a demodulator that demodulates the received signal at a demodulation frequency; and a frequency error processor that determines a frequency error from the local calibration signal at the demodulation frequency, wherein the reference signal generator adjusts a frequency of the first frequency conversion signal used during normal receive operation in response to the frequency error to compe

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A method and apparatus for mixing an input signal in a communications system. The apparatus includes an in-phase mixer, a quadrature mixer, and bias circuits. The in-phase mixer mixes the input signal with an in-phase local oscillator signal. The quadrature mixer mixes the input signal with a quadrature local oscillator signal. The quadrature local oscillator signal is approximately 90° out of phase with the in-phase local oscillator signal. The bias circuits provide DC bias to the in-phase mixer and to the quadrature mixer to balance their outputs.

Abstract: A mixer is described having a Gilbert cell structure including a first input and a second input for inputting an RF signal, a third input and a fourth input for inputting a local oscillator signal, a first output and a second output for outputting an IF signal, a plurality of switches for converting the RF signal to an IF signal, and a dynamic bleed circuit for dynamically reducing the dc-current of the switches at the switching-point. As the dc-current of the switches is reduced at the point of commutation, the 1/f-noise is also strongly reduced without degrading the linearity. The switching happens at twice the local oscillator frequency. The mixer also includes a common mode feedback circuit that feeds the common mode signal, optionally amplified, to a common mode feedback control device that is in series between the dynamic bleed circuit and the supply voltage.

Abstract: Disclosed are systems and methods which utilize a relatively low cost first IF filter in a dual conversion tuner circuit. A preferred embodiment first IF filter is provided using a filter arrangement having a relatively high tolerance. Accordingly, preferred embodiment systems are designed such that they can accommodate the range of first IF frequencies that the large tolerance filter may provide. One aspect of this accommodation may include providing a means by which the system may detect the location of the passband of the IF filter in the spectrum. Another aspect of the accommodation for the range of first IF frequencies may include adjusting the first IF frequency utilized by the dual conversion tuner to match the passband of the IF filter. Additionally or alternatively, the passband of the first IF filter itself may be tuned, such as to provide a passband more near a desired IF frequency.

Abstract: A double conversion tuner system is disclosed that avoids the problem of degraded performance as a result of radiated interferers. Several selection criteria are described for specifying the parameters of the tuner, including the nominal first or high intermediate frequency, a first local oscillator signal for each desired channel, a nominal second local oscillator signal, and a bandwidth of the first intermediate frequency.

Abstract: A demodulation apparatus that can support various oscillation frequencies. The portable phone device includes a frequency synthesizer for generating a local-oscillation signal having a local oscillation frequency for converting the frequency of an input receiving signal into an intermediate frequency based on an oscillation signal generated by an TCXO and a synchronization hold portion provided with an NCO for generating a signal having a predetermined frequency based on the oscillation signal generated by TCXO. The frequency synthesizer makes the local oscillation frequency variable by setting the dividing ratio variable in accordance with an arbitrary oscillation frequency so that the intermediate frequency remains within a predetermined range regardless of the oscillation frequency, and an NCO makes the frequency of the signal variable by setting the dividing ration variable in accordance with the oscillation frequency.

Abstract: A bandpass filtering method in which two frequency transpositions are performed in parallel on an input signal (SE) for filtering using respective first and second upstream mixing signals (SM1, SM2). A common oscillator (LO) is used which is coupled with a first phase shifter (MTM) to produce upstream mixing signals and which is coupled with a second phase shifter (MTV) to produce downstream mixing signals. Phase shifters are used in opposite manner on first and second signals so that each of said first and second signals (VT1, VT2) receives the phase-advanced output signal from one of the two phase shifters and the phase-delayed output signal from the other of the two phase shifters.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A method and device for adjacent channels operation based on downconverting the input signal to an IF signal, filtering the IF signal, and upconverting the filtered IF signal to the original frequency. The present invention is primarily directed to applications involving the use of standard RF transceiver which does not incorporate a high Q filter. Moreover, the present invention may be used with a circular polarized cross recessed corners stacked array antenna in order to further improve its adjacent channels operation performance.

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: An apparatus and method for converting a frequency of a high frequency signal received from an antenna in an ultra wide band communication system transmitting and receiving using at least two reference frequencies. The method includes generating generation frequencies having frequencies set to convert the frequency of the high frequency signal and mixing the frequency of the high frequency signal and the generation frequencies in at least two stages.

Abstract: The embodiments of the present invention provide a configurable homodyne/heterodyne RF receiver including first and second mixers. The configurable homodyne/heterodyne RF receiver functions as a homodyne receiver when the first and second mixers are configured to operate in parallel, and as a heterodyne receiver when the first and second mixers are configured to operate in series. The embodiments of the present invention further provides an RFID reader employing the configurable homodyne/heterodyne RF receiver to facilitate a listen-before-talk function.

Abstract: A radio frequency receiver includes a passive mixer configured to receive and RF signal and a low input impedance circuit configured to receive the output of the passive mixer.

Abstract: A receiver has a first semiconductor chip and second semiconductor chip for receiving signals of a first radio frequency band, and a communication unit for performing communication using signals of a second radio frequency band. A second mixing unit in the second semiconductor chip uses second local signals supplied from a second local signal oscillator when the frequency of first local signals fed from a first-local-signal-output terminal to a first-local-signal-input terminal is within a predetermined range from the second frequency band, or uses first local signals supplied from the first-local-signal-input terminal when the frequency of the first local signals fed from the first-local-signal-output terminal to the first-local-signal-input terminal is out of the predetermined range from the second frequency band.

Abstract: A CATV tuner includes a metallic housing having first through fourth partitioned chambers. In the first through fourth partitioned chambers, a data circuit, an input filter circuit, a first mixer circuit, a first local oscillation circuit, a first intermediate frequency circuit, and other elements are housed. In the fifth partitioned chamber, a second intermediate circuit and an IC including a second local oscillation circuit are housed. With this configuration, the CATV tuner defines an up/down tuner. The third partitioned chamber in which the first local oscillation circuit is housed and the fifth partitioned chamber in which the second local oscillation circuit is housed are located adjacent to each other. Lines and terminals are used both for a first PLL circuit and a second PLL circuit.

Abstract: A ratiometric clock system for an integrated receiver and associated method are disclosed that provide an advantageous solution for combining digital signal processing (DSP) circuitry on the same integrated circuit as mixer and local oscillator (LO) generation circuitry. The generation circuitry generates an oscillation signal that is passed through a first divider to generate mixing signals for the mixer that is passed through a second divider to generate a digital clock signal that is utilized by the DSP circuitry. This digital clock signal can be utilized by integrated analog-to-digital conversion circuitry, as well.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: Integrated multiple tuner architectures and associated methods are disclosed that utilize frequency isolated local oscillators (LO). These architectures utilize dividers and multipliers within the signal paths for the local oscillator mixing signals to reduce interference among the multiple local oscillators operating on a single integrated circuit. A multiple tuner direct-down-conversion (DDC) receiver and a multiple tuner intermediate frequency (IF) receiver are provided as example embodiments. And an example integrated multi-tuner satellite receiver is also described.

Abstract: A direct conversion receiver includes a mixer for converting an RF signal into a baseband signal, a dynamic DC offset compensator for compensating for a dynamic DC offset caused by the effect of second order nonlinear distortion of the mixer on an interfering wave that enters the input terminals of the mixer, and a static DC offset compensator for compensating for a static DC offset caused by self-mixing of a local signal and a leakage component of the local signal that appears at the input terminals of the mixer. The static DC offset compensation starts at a time t1 after a DC offset compensation operation has started. The static DC offset compensation is finished at the next time t2, and then the dynamic DC offset compensation starts. The dynamic DC offset compensation is finished at the next time t3. With this configuration, only a change in DC offset due to the dynamic DC offset is compensated after compensating for the static DC offset component.

Abstract: A modulation-demodulation apparatus of a relatively simple arrangement is able to prevent a bad influence caused due to interference between two local oscillators and a portable wireless communication apparatus uses this modulation-demodulation apparatus. In a modulation-demodulation apparatus using a local oscillator (105) for use in direct conversion type of a receiving system and a local oscillator (104) for use with a transmitting system, a ratio (C/D) between a reception frequency and an oscillation frequency of the reception local oscillator (105) and a ratio (A/B) between a transmission frequency and an oscillation frequency of the transmission local oscillator are made different from each other.

Abstract: Analog-valued floating-gate transistors are used as trimmable circuit components for modifying and/or controlling the gain, phase, offset, frequency response, current consumption, and/or transfer function of signal pathways in parallel and/or serial processing circuits in radio frequency, analog, or mixed-signal integrated circuits.

Abstract: A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

Abstract: A frequency-mixing method includes a step of generating a first quadrature signal having a predetermined frequency, a second quadrature signal having a phase difference of about 180 degrees with respect to a phase of the first quadrature signal, a third quadrature signal having a phase difference of about 90 degrees with respect to the phase of the first quadrature signal and a fourth quadrature signal having a phase difference of about 90 degrees with respect to a phase of the second quadrature signal; a step of controlling a phase of the third quadrature signal and a phase of the fourth quadrature signal so as to control a linearity of a frequency mixer; and a step of down-converting a radio frequency (RF) signal using the first through the fourth quadrature signals. Accordingly, performance of a direct-conversion receiver (DCR) can be improved by employing a frequency-mixing device capable of enhancing a linearity of a frequency mixer.

Abstract: A quadrature subharmonic mixer comprises a polyphase filter configured to generate quadrature components of a local oscillator (LO) reference signal, a summing and scaling element configured to create additional components of the LO reference signal, and a plurality of mixer elements configured to multiply the quadrature components of the LO reference signal and the additional components of the LO reference signal with a radio frequency (RF) signal to obtain a downconverted version of the RF signal.

Abstract: A power amplifier develops a modulated high power signal by summing the outputs of multiple voltage controlled oscillators. A phase control circuit synchronizes the phase relationship of multiple voltage controlled oscillators. The voltage control oscillators provide amplitude modulation of an output signal of the voltage controlled oscillator by adjusting transconductance of amplification devices of the voltage controlled oscillator. Another embodiment of the power amplifier provides buffer circuits at the outputs of the voltage controlled oscillators. The gain or delay of the buffer circuits is varied to provide amplitude modulation of the power amplifier.

Abstract: A method and system is disclosed for transmitting two related channels of signals through the air. A first channel of signals is modulated with a first carrier frequency, and a second channel of signals is modulated with a second carrier frequency. The modulated first channel of signals and the second channel of signals are then combined through a high isolation combiner. Thereafter, the combined signals are transmitted toward a receiver system. After receiving the transmitted signals, the first channel and the second channel of signals are regenerated in the receiver system by separating one from the other.

Abstract: An integrated circuit may include a receiver and/or a transmitter that performs third order sub-harmonic conversion. The integrated circuit may include a Gilbert cell active mixer with three or more serially-connected transistors in each of the mixer's four branches. Alternatively, the integrated circuit may include a quad-ring passive resistive mixer with three or more serially-connected transistors in each of the mixer's four branches. Alternatively, the integrated circuit may include a logic circuit and a mixer. The logic circuit may apply logic operations to periodic logic signals having a local frequency and to delayed versions thereof to produce reference signals having a dominant spectral component at three times the local frequency. The mixer may mix input signals with the reference signals to produce output signals having a dominant spectral component at three times the local frequency less a center frequency of the input signals.

Abstract: The invention provides a receiving system and a transmitting system capable of decreasing an offset between differential signals and between quadrature signals and improving a manufacturing yield and a semiconductor integrated circuit device for processing a wireless communication signal having therein the systems. A receiving system includes: a local oscillator for generating an oscillation signal in a desired frequency; a 90-degree phase-shifting circuit for generating a signal by shifting a phase of the oscillation signal output from the local oscillator by 90 degrees; a first mixer for mixing one of differential reception signals with an output signal of the first 90-degree phase-shifting circuit and outputting frequency-converted differential signals; and a second mixer for mixing another one of the differential reception signals with an output signal of the local oscillator and outputting frequency-converted differential signals.

Abstract: The invention is a system and method for sharing components of a single-path receiver or transmitter system multiple antennas. Specifically, according to one embodiment of the present invention, multiple antennas simultaneously share an analog-to-digital converter unit. The signal from one antenna is downconverted to a positive frequency band while the signal from another antenna is downconverted to a negative frequency band, allowing the signals to be processed by the analog-to-digital converter unit with minimal interference between signals and without the need for time-periodic switching. According to another embodiment of the present invention, multiple antennas simultaneously share a digital-to-analog converter unit.

Abstract: A unique ultra wide band receiver is provided that blends together RF and photonic technologies. The receiver has application as a steering mechanism (600) for a much higher resolution receiver. Some implementations can provide at least four times shorter scanning and processing time than current technology using Bragg-cell technology as a direct replacement for state of the art A/D technology at a high IF frequency conversion rate. The dynamic range offered through use of Bragg-cell processor technology, as used in this IF application, provides greater bandwidth than comparable A/D technology.

Abstract: A wireless terminal circuit includes a variable high frequency clock oscillator that provides a high frequency clock signal and a fixed low frequency clock oscillator that provides a low frequency clock signal. A phase-locked loop adjusts a ratio of the frequency of the high frequency clock signal to the low frequency clock signal by adjusting the frequency of the high frequency clock signal. The phase locked loop includes a divider for dividing the high frequency clock signal, the divide ratio of which divider is controlled by a sigma-delta modulator. A wireless terminal local oscillator calibration circuit includes a frequency control circuit including both the high frequency clock oscillator and the low frequency clock oscillator.

Abstract: A digital baseband (DBB) radio frequency (RF) receiver includes a digital high pass filter compensation (HPFC) module used to suppress group delay variation distortion caused by using low cost analog high pass filters (HPFs) in the receiver. The digital HPFC module reduces a cutoff frequency, established by the HPFs for the real and imaginary signal component frequency domain responses by providing a first compensation signal having a first predetermined value (K1). The digital HPFC module adjusts the gain of the high pass response of the real and imaginary signal component frequency domains by providing a second compensation signal having a second predetermined value (K2).

Abstract: The present invention relates generally to communications, and more specifically to a method and apparatus for generating local oscillator signals used for up- and down-conversion of RF (radio frequency) signals. A major problem in the design of modulators and demodulators, if the leakage of local oscillator (LO) signals into the received signal path. The invention presents a number of highly integratable circuits which resolve the LO leakage problem, using regenerative divider circuits acting on oscillator signals which are running at a multiple or fraction of the frequency of the desired LO signal, to generate in-phase (I) and quadrature (Q) mixing signals. Embodiments of these circuits also use harmonic subtraction and polyphase mixers, as well as virtual local oscillator TM (VLO) mixing signals. VLO mixing signals are signal pairs which emulate local oscillator signals by means of complementary mono-tonal and multi-tonal mixing signals.

Abstract: A receiver apparatus including a main input for receiving the input signal and a first standard mixer having a first mixer input, a first local oscillator input, and a first mixer output. The first mixer input is connected to the main input and the first local oscillator input is connected to a source that provides a first local oscillator signal having a frequency close to or equal to the carrier frequency. The apparatus further including a second mixer with a second mixer input, a second local oscillator input, and a second mixer output. The second mixer input is connected to the main input and the second local oscillator input is connected to a source that provides a second local oscillator signal with an undesired sideband frequency. There are circuit for super-positioning the first output signal and the second output signal. The first local oscillator signal and the second local oscillator signal are square-wave signals.

Abstract: A ratiometric clock system for an integrated receiver and associated method are disclosed that provide an advantageous solution for combining digital signal processing (DSP) circuitry on the same integrated circuit as mixer and local oscillator (LO) generation circuitry. The generation circuitry generates an oscillation signal that is passed through a first divider to generate mixing signals for the mixer and that is passed through a second divider to generate a digital clock signal that is utilized by the DSP circuitry. This digital clock signal can be utilized by integrated analog-to-digital conversion circuitry, as well.

Abstract: A system and method are disclosed for dynamically selecting high-side injection or low-side injection of local oscillator mixing signals based upon an assessment of signal power within the input signal spectrum that could cause unwanted images in the processed signal. This image rejection assessment provides an advantageous basis upon which to make dynamic high-side versus low-side injection determinations.

Abstract: Multistage RF transmitter and receiver circuits may use independently variable RF and IF local oscillators, allowing the RF and IF local oscillator frequencies for a given RF channel to be selected to have a large common factor with respect to the reference oscillator used by the local oscillator circuits, thus allowing the use of small divisor numbers in the local oscillator circuits and reducing phase noise. Independent high-side and low-side RF local oscillators may be provided and selectively used depending on the RF channel to be transmitted or received.

Abstract: This invention includes a wireless transmitter comprising an IF-signal generator that modulates input signals into those of an intermediate frequency band, signal distributors that distribute signals from the IF-signal generator, and a plurality of signal-transmission units that convert the signals distributed by the signal distributors into those of a radio frequency band, and then transmit the converted radio signals. The invention also includes a wireless receiver that receives the radio-frequency-band modulated signals and restores the signals of the intermediate frequency band. In this way, effective diversity is realized and signal interruptions are prevented. In addition, a handy, low-cost wireless communications system is provided.

Abstract: A system for spur cancellation comprises an input, an output, a memory, and a summer. A value corresponding to an energy level of a spur is stored in the memory. The summer is configured to receive an input signal from the input, to receive the value from the memory, to subtract the value from the input signal, and to convey an output signal to the output. The output signal is a difference of the value subtracted from the input signal.

Abstract: A method and device are provided for producing mobile radio signals, which utilize a direct conversion receiver, at least one first and one second local oscillator and one regenerative divider for processing signals according to different mobile radio standards. For generating the intermediate frequency for transmission according to at least one of the mobile radio standards, a division by four in addition to a division by three of the oscillator frequency is also possible.

Abstract: A typical satellite reception system comprises a satellite dish, a low noise block (LNB) and a satellite receiver. The low noise block converts the received signals into lower frequency signals which are fed to the satellite receiver. It is now becoming increasingly desirable for STBs to be fitted with two or more tuners, each having an associated receiver/decoder. This is to allow, for example, a user to watch a satellite television program whilst recording, on a video recorder, a different satellite television channel. However, since a single LNB can only supply signals from either a vertically or horizontally polarised signal, it is not possible to use a single LNB to provide all the desired portions of the incoming satellite signal.

Abstract: One embodiment of a tuner integrated circuit includes two mixer circuits, an IF amplifier circuit, three oscillation circuits, a PLL circuit, and a reference oscillation circuit. A plurality of terminals are provided at two sides of the tuner integrated circuit and are connected to these elements. Among the terminals, at least an oscillator-connecting terminal for connecting an externally provided oscillator to the reference oscillation circuit, a power supply terminal through which a power supply voltage is supplied, and a ground terminal connected to a ground are provided at one side of the tuner integrated circuit. The power supply terminal and the ground terminal are disposed adjacent to the oscillator-connecting terminal such that they sandwich the oscillator-connecting terminal therebetween.

Abstract: A frequency translating repeater (120) for use in a time division duplex (TDD) radio protocol communications system includes local oscillator (LO) circuits (210, 310, and 410) to facilitate repeating by providing isolation, reduced phase noise, reduced pulling, and the like. Tunable LOs (441, 442) can be directly coupled to down-converters (413, 414) and up-converters (426, 427) for increased isolation, reduced phase noise, less stringent frequency accuracy, and a reduced potential for pulling.

Abstract: A PLL frequency synthesizer suitable for improving even a spurious characteristic in a lock state while ensuring a high-speed lockup characteristic to thereby implement satisfactoy communication quality includes a switch circuit interposed between a low-pass filter circuit and a voltage-controlled oscillator controlled based on a control signal to open/close control a feedback loop lying between the low-pass filter circuit and the voltage-controlled oscillator. The switch circuit is opened according to a path-opening instruction of a feedback loop based on the control signal to open the feedback loop, thereby stopping the operation of the feedback loop. If this stop operation is controlled according to the control signal so as to he carried out during a period in which a pseudo correction pulse is outputted from a charge pump circuit for each phase comparison cycle of a phase comparator, then spurious generation incident to the pseudo correction pulse can be suppressed.

Abstract: A method is provided for operating a plurality of overlapping wireless networks such that they do not interfere with each other. This is accomplished by having each network transmit at a frequency that is offset from a base frequency by an integer multiple of an offset frequency. The offset frequency is generally a small fraction of the base frequency so that the spectral properties of each network are roughly the same. However, each network will transmit at a unique frequency with respect to all of the other overlapping networks. The offset values are preferably symmetrical around zero, and the offset for one network can be zero.

Abstract: A pole switch down-converter with symmetric resonator which reduce the non resonating phase to approximately half of the RF carrier period of the modulated signal is proposed. The down-converter comprises a first and second ?/2 resonator for collecting RF energy, wherein a differential RF signal is coupled to the first and second ?/2 resonator, a switching means coupled at one end of the first ?/2 resonator and one end of second ?/2 resonator for connecting the first and second ?/2 resonator, a control means for controlling the switching means, and a detecting means coupled to the first and second ?/2 resonator for detecting the down-converted signal, wherein the control means is adapted to initiate in a down-conversion cycle the switching means to connect the first and second ?/2 resonator for approximate half of the RF carrier period of the modulated signal. With this pole switch down-converter adjacent RF channels can be selected and down-converted by slightly varying the pole switch repetition rate.

Abstract: A direct conversion receiver (DCR) calibrated for phase and gain mismatch is provided. The DCR comprises a poly-phase filter that generates mismatched in-phase and quadrature-phase differential signals; the in-phase differential signal is mixed with first and second local oscillation signals; the quadrature-phase differential signal is mixed with third and fourth local oscillation signals; the first and second local oscillation signals have a first adjustable phase mismatch, and the third and fourth oscillation signals have a second adjustable phase mismatch; A mismatch estimation unit (MEU) estimates the entire phase/gain mismatch (signal distortion) of the DCR, The first and second adjustable phase mismatches are adjusted so that the signal distortion of the DCR, as estimated by the MEU is minimized. Thereafter, reduced-component DCRs (without an MEU), calibrated for the mismatches of a poly-phase filter, may be mass produced.