Abstract: The disclosure relates to technology for generating multi-phase signals. An apparatus includes 2{circumflex over (?)}n phase signal generation stages. The apparatus also includes a controller configured to provide a mode input of each of the 2{circumflex over (?)}n stages with an active periodic binary signal with remaining inputs of each of the 2{circumflex over (?)}n stages provided with another periodic binary signal to collectively generate a 2{circumflex over (?)}n phase signal in a first mode.

Abstract: A device for a single wire digital bus, includes an interface for the bus configured to receive a request to arbitrate for an address and to transmit device specific data on the bus upon receipt of the request to arbitrate for an address The device further includes a control circuit configured to determine, if a further device transmits device specific data on the bus, and to use the address arbitrated for, if no further device transmits device specific data on the bus.

Abstract: An apparatus is provided for generating a transmission wave. The apparatus includes a plurality of antennas and a plurality of signal generators. The plurality of antennas has polarization diversity. The plurality of signal generators are each coupled to one of the antennas and configured to generate a continuous twisted wave by driving each of the antennas using independent, coordinated, and distinct sinusoidal waves, and having a twist frequency and a carrier frequency, the twist frequency lower than the carrier frequency. A method is also provided.

Abstract: A system, a method, a device, and a computer program for detecting, monitoring and logging smoking activity related data. The device can comprise a housing, a power supply located within the housing, an atomizer electrically coupled to the power supply, a liquid solution fluidly coupled to the atomizer, and a data logging device configured to be located within the housing and that can comprise a microcontroller, a memory, and a data interface. The data logging device can be configured to detect, monitor, and log smoking activity data, and a data logging device that can comprise a microcontroller, a memory, and a data interface. The data logging device can be configured to detect, monitor, and log smoking activity data.

Abstract: An example device includes splitter logic to split an input sample having a predetermined number of bits into a first segment of most significant bits and a second segment of least significant bits. Pulse logic generates a pattern of pulses that correlate to the values of the most significant bits. Edge mover logic determines edge adjustment data based on the values of the least significant bits, the edge adjustment data representing an adjustment to at least one edge in the pattern of pulses. Combiner logic generates an enhanced pulse stream by adjusting at least one edge in the pattern of pulses based on the edge adjustment data.

Abstract: The present application is directed to an electronic device that has a receiver configured to receive data from a second electronic device and identify potential sync header locations within a portion of the data by performing a mutually exclusive or (XOR) logic operation on a plurality of sequential pairs of bits of the data. Additionally, the receiver is configured to identify sync headers in the data by determining which of the potential sync header locations is shared in subsequent portions of the data.

Abstract: A transmission apparatus and method include modulating a transmission signal using a first modulation scheme selected from a plurality of modulation schemes to generate a first symbol sequence. A second symbol, generated using a phase shift keying (PSK) modulation scheme, is inserted in the first symbol sequence to generate a first modulation signal for transmission. A second modulation signal is received that includes a third symbol generated using a PSK modulation scheme and inserted in a second symbol sequence generated using a second modulation scheme selected from the plurality of modulation schemes. The third symbol is extracted from the received modulation signal. A transmission path associated with the received modulation signal is estimated using the third symbol. A received data signal from the second symbol sequence included in the received modulation signal is output using the estimated transmission path.

Abstract: Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

Abstract: A transmission apparatus and method include modulating a transmission signal using a first modulation scheme selected from a plurality of modulation schemes to generate a first symbol sequence. A second symbol, generated using a phase shift keying (PSK) modulation scheme, is inserted in the first symbol sequence to generate a first modulation signal for transmission. A second modulation signal is received that includes a third symbol generated using a PSK modulation scheme and inserted in a second symbol sequence generated using a second modulation scheme selected from the plurality of modulation schemes. The third symbol is extracted from the received modulation signal. A transmission path associated with the received modulation signal is estimated using the third symbol. A received data signal from the second symbol sequence included in the received modulation signal is output using the estimated transmission path.

Abstract: Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

Abstract: A technique for generating a phase modulated, constant envelope transmit signal having continuous phase transitions between adjacent symbols involves generating a stream of symbols having a sequence of symbol states and identifying antipodal phase transitions between adjacent symbols representing different states. The phase rotation polarity of the continuous phase transitions between adjacent symbols having antipodal phase transitions is controlled such that a phase rotation polarity pattern of the antipodal phase transitions in the stream of symbols is uncorrelated with the sequence of symbol states. The constant envelope transmit signal is then generated from the stream of symbols. The spectral profile of the constant envelope signal can be tailored by selection of the phase trajectory shape and the portion of the symbol over which the continuous phase transition occurs.

Abstract: A transmission method includes modulating a transmission signal using a modulation scheme selected from a plurality of modulation schemes, to generate a first symbol sequence and generating at least one second symbol including a pilot symbol generated using a PSK modulation scheme. The method includes changing an insertion interval of the second symbol to be inserted in the first symbol sequence, to generate a modulation signal and transmitting the modulation signal. The second symbol is configured for synchronization in a reception apparatus.

Abstract: Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

Abstract: Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

Abstract: A modulator for an electrical signal comprises a data input port and a clock frequency input port. The modulator also comprises a first phase shifter for subjecting input clock frequency signals to a phase shift and adapted to keep the phase of an input clock frequency signal aligned with the phase of a data stream which is input at the data input port. The modulator also comprises a first XOR gate with an output port, to which first XOR gate said input ports of the modulator are connected, by means of which a BPSK signal is created at the output port when a first data stream is connected to the data input port and a first clock frequency signal is connected to the clock frequency input port.

Abstract: A method and system is provided for communicating distinct data over a single frequency using on-off keying, a form of amplitude modulation, or phase changes timed to the zero crossing point of the carrier. A data signal is synchronized with the carrier by adding padding bits so that the number of bits is equal to the frequency of the carrier. The carrier is then modified by attenuating the carrier as needed once per cycle. Said carrier is then transmitted. The resulting transmitted carrier carries a number of bits equal to the transmit frequency. At the receive end, the received signal is compared to a sine wave to determine if the incoming signal is at full strength or at reduced strength, allowing for the detection of encoded digital information. In a another embodiment, the phase of the carrier is changed instead of attenuating the carrier, timed to the carrier cycles, once or twice per cycle.

Abstract: An apparatus for phase modulation includes a delay locked loop configured to generate from a reference signal a plurality of phase shifted signals, each of the phase shifted signals being locked to the reference signal and having a different phase shift from the other phase shifted signals with respect to the reference signal, and a multiplexer configured to select one of the phase shifted signals.

Abstract: Polar feedback architecture. A polar modulator, as may be implemented within a transmitter module, of a communication device includes feedback. This feedback involves monitoring of phase information and magnitude/amplitude information of an output signal generated by the polar modulator. The output signal can be a radio frequency (RF) signal such as may be transmitted via a communication channel within a communication system. A baseband processing module processes the monitored phase information and magnitude/amplitude information to perform adjustment of a phase modulator and/or other components within the polar modulator.

Abstract: Enhanced granularity operational parameters adjustment of components and modules in a multi-band, multi-standard communication device. For supporting two-way communications, a communication device includes receiver and transmitter modules. Each module includes various components that are configurable and/or programmable based on a protocol and band pair by which the communication device is operating. The communication device is a multi-protocol and multi-band capable communication device capable to operate in accordance with any one protocol and band at a first time and another protocol and band at a second time. The various components within each of the receiver and transmitter modules can be adjusted using one or more operational parameters. In some instances, a given component can be controlled by more than one operational parameter. Alternatively, certain components are controlled only one operational parameter.

Abstract: An integrated circuit device has a modulator module that provides a modulation signal comprising one frequency keyed on and off, or alternating between two or more different frequencies or phases that are selected based upon a modulator signal. The one or more frequencies or phases may be selected from a plurality of frequency sources. Switching the one frequency on or off, or between the at least two different frequencies or phases may be synchronized with one or both of the two or more different frequencies or phases so that “glitches” or spurs are not introduced into the modulation signal. The integrated circuit device may also comprise a processor, memory, digital logic and input-output. Frequency sources may be internal to the digital device or external. The modulator signal may comprise serial data generated from the digital logic and/or processor of the digital device.

Abstract: A quadrature amplitude modulator is provided. An oscillator generates an in-phase carrier signal having a rectangular wave, a trapezoidal wave or a waveform similar to these, and a quadrature carrier signal, the phase of which is shifted by ¼ cycle relative to the in-phase carrier signal. A multi-level driver generates an in-phase modulated signal by amplitude modulating the in-phase carrier signal with an analog in-phase baseband signal having a discrete voltage level or current level in accordance with the in-phase baseband data. Likewise, the multi-level driver generates a quadrature modulated signal by amplitude modulating the quadrature carrier signal with an analog quadrature baseband signal having a discrete voltage level or current level in accordance with the quadrature baseband data The multi-level driver generates a modulated signal, the amplitude of which takes a discrete level, by combining the modulated signals together.

Abstract: The method and system are disclosed for automatic feedback control of integrated optical quadrature modulator for generation of optical quaternary phase-shift-keyed signal in coherent optical communications. The method comprises the steps of detecting at least a part of an output optical signal from the QPSK modulator, extracting of a particular portion of the output signal in frequency domain, and processing the signal in frequency domain to optimize the transmission of an optical link. The system and method of optical communications in fiber or free space are disclosed that implement the quadrature data modulator with automatic feedback control.

Abstract: An apparatus for phase modulation includes a delay locked loop configured to generate from a reference signal a plurality of phase shifted signals, each of the phase shifted signals being locked to the reference signal and having a different phase shift from the other phase shifted signals with respect to the reference signal, and a multiplexer configured to select one of the phase shifted signals.

Abstract: Provided is a digital modulator, including a carrier wave output section that outputs a carrier wave, a variable delay section that delays the carrier wave, and a delay amount setting section that sets a delay amount by which the variable delay section delays the carrier wave based on transmission data being transmitted by the carrier wave. The variable delay section may include a multi-stage delay buffer circuit in which delay buffers that delay an input signal by a unit shift amount are connected in a cascade connection, the multi-stage delay buffer circuit may receive the carrier wave at a first-stage delay buffer as input, and the delay amount setting section may include a multiplexer that selects either an output from the carrier wave output section or an output from each stage of the multi-stage delay buffer circuit.

Abstract: A multi-phase ultra-wideband signal generator uses differential pulse oscillators. The multi-phase ultra-wideband signal generator using differential pulse oscillators includes N pulse oscillators for generating pulse signals based on a supply of power, and further comprises N inverting amplification units for outputting inverted amplified signals of output signals of the N pulse oscillators when a number of pulse oscillators is at least two, wherein, when the number of pulse oscillators is an even or odd number, the pulse oscillators are arrayed such that they have a connection form in which output terminals OUT(+) and OUT(?) of a relevant pulse oscillator are connected to output terminals OUT(+) and OUT(?) of a next pulse oscillator through a relevant inverting amplification unit, and the connection form is consecutively applied to the pulse oscillators.

Abstract: A modulator for an electrical signal comprises a data input port and a clock frequency input port. The modulator also comprises a first phase shifter for subjecting input clock frequency signals to a phase shift and adapted to keep the phase of an input clock frequency signal aligned with the phase of a data stream which is input at the data input port. The modulator also comprises a first XOR gate with an output port, to which first XOR gate said input ports of the modulator are connected, by means of which a BPSK signal is created at the output port when a first data stream is connected to the data input port and a first clock frequency signal is connected to the clock frequency input port.

Abstract: The present disclosure relates to I/Q modulation circuits, devices, and methods.

Abstract: Disclosed herein is a method and apparatus used to add high-performance phase modulation to an applied input signal with data or clock edges which overcomes limitations of range, bandwidth and operating data rate by utilizing parallel devices to singularly modulate rising and falling edges separately and then re-add them together. In an embodiment of this invention, T-type (toggle) flip flops and exclusive-OR gates are used to achieve very high-performance results.

Abstract: A simple, interference-free digital phase modulator is to be provided. To this end, the phase modulator is provided with a counter for outputting a counter signal on the basis of a predetermined clock signal and a comparator, which receives a current counter state from the counter, in order to record a digital input signal. The comparator compares the input signal with the current counter state on the basis of a predetermined allocation table and resets the counter, if the input signal corresponds to a counter state assigned via the allocation table. A predetermined signal value of the output counter signal is herewith phase-modulated as a function of the input signal. As only one phase position is generated with the circuit at any point in time, interferences, which are produced by the digital phase modulator itself, are significantly less.

Abstract: A modulator for radio-frequency signals designed an entirely digital modulator has two mixer stages connected in series. The first mixer stage implements with a relatively low first sample rate a frequency mixing with a first oscillator frequency that is adjustable with high precision. The second mixer stage implements a frequency mixing with a significantly higher second sample rate and with a relatively coarsely adjustable second oscillator frequency. The downstream second mixer stage, in the case of a single mixer stage, the mixer stage, has at least two phase accumulators that are incremented with the higher second sample rate but with different incremental values. The output signal of at maximum one of the phase accumulators is evaluated at any point in time.

Abstract: In a radio communication system, transmitter and receiver stations share information on a maximum number of bits communicated per symbol. The transmitter station encodes a signal with sufficient error correcting capabilities to create a codeword. The transmitter station allocates the bits from the codeword to each symbol, modulates the symbols using a modulation type which processes symbols each having a number of bits equal to or smaller than the maximum number of bits per symbol, and transmits the modulated symbols. The receiver station demodulates the symbols using a modulation type which processes a larger number of bits per symbol as the transmission path quality is higher from among modulation types which process symbols having a number of bits equal to or smaller than the maximum number of bits per symbol.

Abstract: Provided is a digital modulator, including a carrier wave output section that outputs a carrier wave, a variable delay section that delays the carrier wave, and a delay amount setting section that sets a delay amount by which the variable delay section delays the carrier wave based on transmission data being transmitted by the carrier wave. The variable delay section may include a multi-stage delay buffer circuit in which delay buffers that delay an input signal by a unit shift amount are connected in a cascade connection, the multi-stage delay buffer circuit may receive the carrier wave at a first-stage delay buffer as input, and the delay amount setting section may include a multiplexer that selects either an output from the carrier wave output section or an output from each stage of the multi-stage delay buffer circuit.

Abstract: A channel alignment system in an optical communication network includes logic to sample power of a quadrature amplitude modulation (QAM) channel at a component downstream from a QAM modulator. The system determines if the sampled channel power has a sufficient level. The system signals power control logic of the QAM modulator to adjust a gain of the sampled channel.

Abstract: A system and method of the present invention forms a hybrid encoded signal. A signal generator generates a coded waveform having a trellis structure, such as a continuous phase modulated signal. A modulator is operative with the signal generator and adds at least one orthogonal or amplitude modulated waveform to a trellis structure of the coded waveform to create a non-constant envelope modulated signal that has at least one of increased bandwidth, improved bit error rate, or an increased number of bits encoded into a single symbol.

Abstract: A novel apparatus and method for a fully digital quadrature architecture for a complex modulator. The complex modulator can substitute for existing prior art analog quadrature modulator structures and those based on a digital polar architecture (r, ?). The modulator effectively operates as a complex digital-to-analog converter where the digital inputs are given in Cartesian form, namely I and Q representing the complex number I+jQ, while the output is a modulated RF signal having a corresponding amplitude and phase shift. The phase shift being with respect to a reference phase dictated by the local oscillator, which is also input to the converter/modulator. Several embodiments are provided including modulators incorporating dual I and Q transistor arrays, a single shared I/Q transistor array, modulators with single ended and differential outputs and modulators with single and dual polarity clock and I/Q data signals.

Abstract: A linearization system is provided for a Fractional-N Offset Phase Locked Loop (FN-OPLL) in a frequency or phase modulation system. In general, the linearization system processes a modulation signal to provide a linearized modulation signal to a fractional-N divider in a reference path of the FN-OPLL such that a frequency or phase modulation component at the output of the FN-OPLL is substantially linear with respect to the modulation signal.

Abstract: A simple, interference-free digital phase modulator is to be provided. To this end, the phase modulator is provided with a counter for outputting a counter signal on the basis of a predetermined clock signal and a comparator, which receives a current counter state from the counter, in order to record a digital input signal. The comparator compares the input signal with the current counter state on the basis of a predetermined allocation table and resets the counter, if the input signal corresponds to a counter state assigned via the allocation table. A predetermined signal value of the output counter signal is herewith phase-modulated as a function of the input signal. As only one phase position is generated with the circuit at any point in time, interferences, which are produced by the digital phase modulator itself, are significantly less.

Abstract: An IQ-modulator pre-distorter includes an iteratively updated digital filter (gQ0, gQ1) for filtering one of the branches of an IQ-signal to compensate for IQ-modulator generated amplitude errors. An iteratively updated digital filter (cQI0, cQI1), cross-connected from one of the branches to the other branch, filters one of the components of an IQ-signal to compensate for IQ-modulator generated inter-modulation between the branches. Iteratively updated compensators (dcI, dcQ) counteract IQ-modulator generated offset errors.

Abstract: A modulator (10) and method provides a programmable phase rotation for supporting different modulation formats and different phase rotations. The modulator (10) includes a programmable symbol counter (32) and symbol phase rotation logic (31) operatively responsive to programmable phase rotation size data (36) and programmable counter size data (30). The modulator (10) can be used to communicate with different modulation formats employing different phase rotation conventions as used in different communication systems. The symbol phase rotation logic (31) produces rotated in-phase data (20) and rotated quadrature data (22) in response to receiving at least received symbol data (24), programmable phase rotation size data (36), and symbol count data (32) based on programmable counter size data (30). According to another embodiment, the phase rotations of the modulator (10) may be dynamically selectable such that the phase rotations may be selected to accommodate changes in channel characteristics in real time.

Abstract: A mixer circuit accumulates I signal (digital signal of first channel) having its band limited by low-pass filter and first carrier signal to perform two-phase shift keying modulation thereon. An adder adds fundamental-wave component of bit clock signal BCK into Q signal (digital signal of second channel) having its band limited by the another low-pass filter to obtain a resultant added-up signal. Another mixer circuit accumulates the added-up signal and second carrier signal to perform two-phase shift keying modulation thereon. Output signals of the mixer circuits are input to another adder so that they may be added up to obtain a QPSK signal as a modulated quadrature signal. The QPSK signal contains frequency signals whose frequencies are a sum of bit clock frequency and carrier frequency and a difference between them. When demodulating, the carrier signal and the bit clock signal are reproduced using the frequency signals.

Abstract: There is provided a quadrature modulation transmitter which is capable of solving several problems of the conventional transmitter while performing the same function as the heterodyne transmitter or the digital IF transmitter, in which a circuit structure is simplified and a power consumption is reduced compared with the conventional transmitter.

Abstract: A ring oscillator of an even number of stages of inverting/summing amplifiers that adds, to an input of each of the amplifiers, a signal from one such of the amplifiers as to be distant by an even number of stages therefrom, to realize a desired oscillation operation, thereby directly generating signals having phases shifted by 90 degrees from each other. Further, the signals in the ring oscillator are complementary to each other, so that by arranging these signals close to each other in a wiring, it is possible to realize low sensitivity to a mixed external signal.

Abstract: A transmitter and a receiver share a maximum number of transmission bits per symbol as a parameter. The transmitter modulates an encoded and interleaved transmission signal in accordance with a modulation scheme which enables the transmission of one bit or more per symbol, while the receiver demodulates a received signal based on a channel quality in accordance with a modulation scheme which has a higher modulation level as the channel quality is higher. When the number of demodulated bits per symbol is smaller than the maximum number of transmission bits per symbol, the receiver deinterleaves and decodes a received signal after the demodulation on the assumption that the received signal has likelihoods of zero as much as the number of missing bits.

Abstract: The invention relates to a phase shifted binary transmission encoder with data input and data output, where the phase shifted binary transmission encoder includes an exclusive or gate having two inputs and one output, the output of the exclusive or gate being the output of the Phase shifted binary transmission encoder, where one input of the exclusive or gate is connected with the output via a first delaying element and the other input of the exclusive or gate is connected with the data input via a second delay element, both delaying elements being connected with a clock input, wherein the delay elements are transparent D flip-flops. Furthermore the invention relates to a phase modulator and an optical network element for phase shaped binary transmission.

Abstract: A high-speed transmitter for digital data having a variable data rare, the transmitter comprising a convolutional encoder, adapted to generate, for each group of k input bits in a bitstream, n coded output bits, such that k and n are integers, n equal to or greater than k, and at least one of k and n is variable responsive to the variable data rate of the transmitter; and a modulator, coupled to map the output bits generated by the encoder to a constellation of M symbols for transmission by the transmitter, M an integer, which is variable responsive to the variable data rate of the transmitter; and wherein for a given rate Rs of transmission of the symbols by the transmitter, the variable data rate Rb is given by Rb=Rs*log 2(M)*Rc, wherein Rc is a code rate equal to k/n.

Abstract: A Multi-mode Loop Frequency modulator (10) for modulating a carrier signal according to various modulation pulse shapings and data signal to provide a modulated output signal (VCOout), comprises a waveform generator (12) and two multiplexors (14,38) to perform various pulse shaping filtering and or predistord the pulse shaping filter impulse response for either a dual port modulation or for a single port modulation. The waveform generator (12) can also provide interpolation to input frequency deviation and also provide scaling for various reference frequency clock provided by the crystal (30) and the reference divider (28). The low pass filter (22) is used for providing the PLL loop filtering and also as the smoothing filter for the high port DAC (18).

Abstract: The invention relates to a system for electromagnetic processing of an input wave involving receiving a modified signal derived from two or more signals that represent the input wave when combined; and alternately regulating the modified signal using a digital signal containing at least one characteristic of said two or more signals. The invention may utilize in-phase and quadrature phase signals, where the magnitude portion of the signals may be used for regulating the modified signal. The modified signal may be created by modulating a characteristic of the I, Q signals, such as their sign, with an RF or other frequency carrier wave.

Abstract: A transmitter for transmitting a high frequency transmit signal generates a low intermediate frequency quadrature signal, and up-converts the low intermediate frequency quadrature signal to the high frequency transmit signal. The frequency spectrum of the high frequency transmit signal has a transmit band and a sideband corresponding to the transmit band. The transmit band is confined to a total transmit band outside of which severe sideband filtering requirements.apply. Before up-converting, the transmitter provides that the sideband falls at a side of the transmit band such that the sideband falls within the total transmit band.

Abstract: A modulator for modulating carrier wave signals with an in-phase component signal and a quadrature component signal includes a fixed frequency signal generator for generating two fixed-frequency signals differing 90 degrees in phase, a variable frequency signal generator for generating a signal whose frequency can be varied according to a modulated signal, in-phase and quadrature component carrier wave signal generators for mixing respective ones of the fixed-frequency signals and the variable-frequency signal to generate carrier wave signals for in-phase and quadrature components, an in-phase component modulator for modulating the in-phase component carrier wave signal with the in-phase component signal, and a quadrature component modulator for modulating the quadrature component carrier wave with the quadrature component signal. Also, a demodulator is able to demodulate an in-phase component modulated signal and a quadrature component modulated signal from the modulator.

Abstract: A wideband impedance attenuator includes a phase-locked loop filter, a voltage-controlled oscillator connected to the phase-locked loop filter during transmit, and an impedance circuit connected to the phase-locked loop filter and the voltage controlled oscillator. The impedance circuit is a scaled version of the phase-locked loop filter. Moreover, the wideband impedance attenuator attenuates a Gaussian frequency shift key modulation signal by a factor of 1/(N+1) using the impedance circuit, which has an impedance of N*Z(s), and the phase-locked loop filter, which has an impedance of Z(s). An output frequency is generated using a voltage-controlled oscillator wherein the output frequency corresponds to the attenuated Gaussian frequency shift key modulation signal. In addition, a comparator compares a voltage of an output from the programmable gain amplifier with a voltage necessary to produce a predetermined frequency shift in a voltage-controlled oscillator to produce a gain signal.