Abstract: A communication device effectively transmits high-speed data while being less affected by restrictions of an environment by adjusting a communication channel depending on an optical communication environment.

Abstract: Disclosed are a method and apparatus capable of enhancing a closed loop multi-input multi-output (MIMO) capacity through distributed discrete power control in the case of cooperatively transmitting information to multiple users through a downlink.

Abstract: An apparatus is disclosed where a Powerline interface is used to transmit data into the powerline grid network, where the powerline interface is pulling the required transmit energy from the power grid network, where the powerline interface is transmitting data using standard narrow band modulation such as ASK, FSK, S-FSK, where the transmitted data are passed on to the powerline interface by the use of an “Input signal” adapation stage, where an error calculation and a comparison to a “Triangle” signal is performed to create a command signal used to enable the transmission of data by providing enough voltage to polarize the Transistor (i.e: MOS FET) used in the powerline path.

Abstract: One embodiment of the present invention sets forth a mechanism for transmitting and receiving ground-referenced single-ended signals. A transmitter combines a direct current (DC) to DC converter including a flying capacitor with a 2:1 clocked multiplexer to drive a single-ended signaling line. The transmitter drives a pair of voltages that are symmetric about the ground power supply level. Signaling currents are returned to the ground plane to minimize the generation of noise that is a source of crosstalk between different signaling lines. Noise introduced through the power supply is correlated with the switching rate of the data and may be reduced using an equalizer circuit.

Abstract: A communications device may include In-phase (I) power amplifiers configured to generate I amplified signals, Quadrature (Q) power amplifiers configured to generate Q amplified signals, an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers. The communications device may also include a power combiner configured to combine the I amplified signals and the Q amplified signals in a combined amplified signal, and an antenna coupled to the power combiner.

Abstract: A communications device may include In-phase (I) power amplifiers configured to respectively generate I amplified signals, Quadrature (Q) power amplifiers configured to respectively generate Q amplified signals, I antennas respectively coupled to the I power amplifiers, and Q antennas respectively coupled to the Q power amplifiers. The communications device may also include an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers.

Abstract: A communications device may include an In-phase (I) power amplifier configured to generate an I amplified signal, a Quadrature (Q) power amplifier configured to generate a Q amplified signal, an I digital-to-analog converter (DAC) configured to generate an I signal, and a Q DAC configured to generate a Q signal. The communications device may also include an I power supply circuit coupled to the I power amplifier and to the I DAC and configured to cause the I power amplifier to modulate an I carrier signal into the I amplified signal based upon the I signal, a Q power supply circuit coupled to the Q power amplifier and to the Q DAC and configured to cause the Q power amplifier to modulate a Q carrier signal into the Q amplified signal based upon the Q signal, and at least one antenna coupled to the I and Q power amplifiers.

Abstract: Provided is a transmission circuit capable of compensating a variation in output power caused due to a temperature change or an individual variability when the operation mode is switched without an increase in the size of the transmission circuit which switches the operation mode between a linear operation mode and a nonlinear operation mode, and capable of suppressing the deterioration of the quality of a transmission signal. In the transmission circuit, a gain setting section (160) sets the gain (target gain) of a variable gain amplifier (140), to a value which enables the variable gain amplifier (140) to operate linearly and corresponds to a comparison result (output error level) obtained through comparison between the target level of the variable gain amplifier (140) corresponding to the set power level of the transmission signal and the power level of an output signal of the variable gain amplifier (140) detected by a power detection section (150).

Abstract: The invention relates to information transmission methods, in particular to the communication interfaces of electronic devices. The inventive method makes it possible to increase the communication range and reliability by improving noise protection through the compensation of a noise signal during the transmission and reading of the signal in both wires of a communication line. The inventive method involves connecting the first pole of a voltage supply source to the first wire of a two-wire transmission line via a first resistor and connecting the second pole of said voltage supply source to the second wire of the two-wire transmission line via a second resistor. Moreover, the first and second resistors have the equal resistance values, and a receiver is connected to the two-wire transmission line between a transmitter and the voltage supply source and is provided with two current sensors. A reading signal is defined as the sum of absolute values of the measured currents.

Abstract: The present invention concerns the field of power amplifiers and in particular the enhancement of the performance of the amplifier by a feedback loop acting on the input signal. We present a method for linearizing a power amplifier circuit having as input signal a digital base-band input signal, (x), a power output signal 8z), a power amplifier (PA) and a linearizer module (LM).

Abstract: Peak power reduction in transmit chains of multi-band radiocommunication devices is performed. By using knowledge of the phase transformations which occur at the upconverter to determine how baseband signal samples will combine at the higher (upconverted) frequency, peak prediction and corresponding baseband signal modification can be performed in a way that reduces peak power of the combined signal.

Abstract: A powerline communications device comprises a powerline communications interface and at least one other communications interface configured to communicate over a computing network. The powerline communications interface is further configured to receive electrical power. The computing network may comprise mediums including powerlines, telephone lines, and/or coaxial cables. In some embodiments, the powerline communications interface may communicate with a network apparatus, such as a personal computer, via an Ethernet interface. The powerline interface, the telephone line interface, and/or the coaxial cable interface may all be associated with the same media access control (MAC) address. The powerline communications device may receive a message via a first medium and repeat the message via a second medium based on a quality of service (QoS) metric. In some embodiments, the powerline communications device may communicate using multiple frequency bands.

Abstract: An apparatus comprises at least one transmit amplifier and rectification circuitry located in the at least one transmit amplifier, which is configured to receive a RF signal and provide a rectified voltage, which is selectably added to a voltage supplied by a battery to generate a DC voltage supply signal that is a function of RF power level. A controller is configured to select between providing the VBAT or the VSupply signal to a transmit switch depending on one or more of a logic state and a mode of operation. An alternate apparatus comprises a charge pump circuit configured to quickly raise a voltage supplied to it and store the output voltage on a capacitor and then either shift a first frequency provided by a charge pump oscillator to a lower second frequency or turn off a charge pump clock to maintain a voltage on the capacitor during a transmit mode.

Abstract: A radio communication device includes a power amplifier to amplify a transmit signal, a control unit to generate a voltage control signal for defining power to be supplied to the power amplifier in accordance with a conversion curve expressed using a polynomial series based on an envelope signal obtained from the transmit signal and determine the polynomial series based on an efficiency of the power amplifier, and a power source unit to supply the power to the power amplifier based on the voltage control signal, wherein the control unit divides an amplitude range of the envelope signal on the conversion curve into a plurality of sections and determines the polynomial series based on at least one of the plurality of sections.

Abstract: A multi-valued driver circuit selectively outputs, to a transmission line, one from among multiple voltages according to a selection signal. A memory circuit stores setting data which define the respective levels of the multiple voltages. According to the selection signal, a selector circuit selects one from among the multiple setting data stored in the memory circuit. A Thevenin termination circuit outputs a voltage that corresponds to the upper M bits of the data thus selected by the selector circuit. An R-2R ladder circuit outputs a voltage that corresponds to the lower Nl bits of the data thus selected by the selector circuit.

Abstract: Herein described are at least a method and a system for transmitting high speed wireless data from a first communication device to a second communication device. The method comprises using a first physical layer for transmitting management data or control signals between the first and second devices. In one embodiment, the management data may be used to authenticate and assign an appropriate wireless communication channel between the first and second device. The wireless communication channel is established by implementing a second physical layer in each of the first and second devices. The wireless communication channel may be used to transmit the high speed wireless data. The system comprises a first communication device and a second communication device wherein each of the first communication device and the second communication device utilizes a first physical layer and a second physical layer.

Abstract: A radio transmission apparatus according to the present invention detects an output current of a power supply section that varies in response to a variation of the output impedance of an amplification section, and corrects a distortion of the input/output characteristic of the amplification section by using an LUT corresponding to the detected output current. In addition, a threshold used for switching an LUT is caused to be different depending on a switching direction between LUTs, thereby suppressing frequent occurrence of switching of the LUT.

Abstract: A high frequency signal switching apparatus includes a bias unit which transmits a bias power source; a control signal transmitter, which provides a control signal received from outside; and a switching unit, so that the input signal input through the input terminal by switching one or more diodes according to the control signal driven by the bias power source is output selectively on the output terminal.

Abstract: A transceiver circuit having 10 mb and 100 mb transmit and receive circuitries using the power saving methods of the present invention is disclosed. The power consumption of the transceiver circuit can be significantly reduced by providing each defined subcircuit with its own power supply and means of activation and deactivation. However, the method for activating and deactivating digital subcircuits and analog subcircuits are different and therefore different types of control signals and methods are provided. Furthermore, there are two general types of power-saving situations. The first type is near total circuit power-down and the second type is partial circuit power-down. The present invention in yet another embodiment discloses a method for minimizing energy usage during idle period.

Abstract: The present invention relates to an apparatus (100), a base station (500) and a method for reducing peak power of an input signal (1) using successive processing stages (10). Each stage (10) comprises a peak finder (11) arranged to find at least one peak of the input signal (1) exceeding a threshold level, and to make a list (LO) comprising information on a number of the highest peaks or information on each peak; a peak selector (12) adapted to receive the list (LO) and to receive, from each preceding stage (10), a list (Li) with information on unreduced peaks and the stage number. The peak selector (12) further selects from all lists a peak (P) to be reduced and determines a fractional sample shift value (FSi) of the stage in which the selected peak was found. Each stage (10) further comprises a kernel selector that selects a kernel signal (Ki) that is fractionally sample shifted with the sum of all fractional shift values, starting from the shift value (FSi) up to the present stage.

Abstract: A microprocessor control unit (MCU) is mounted on a printed circuit board. The MCU includes first and second clocked serial interface (CSI) circuits. The first CSI circuit is configured to serially transmit a first xCP packet to a first encoder circuit, which in turn is configured to generate an encoded first xCP packet as a function of the first xCP packet and a first clock signal. A first low voltage differential signal (LVDS) circuit is coupled to the first encoder circuit and configured to serially receive the encoded first xCP packet therefrom. The first LVDS circuit is configured to generate a first differential signal as a function of the encoded first xCP packet.

Abstract: Wired/wireless optical signal modulation and demodulation apparatuses and methods using an intensity modulation/direct detection method and an orthogonal frequency division multiplexing (OFDM) method are provided. A unipolar OFDM symbol frame is generated by determining the polarity of each of a plurality of sub-frames of a bipolar OFDM symbol frame which comprises both a plurality of positive pulses and a plurality of negative pulses, inverting the polarity of the sub-frames which are determined to be negative, delaying one of the positive sub-frame and a positive sub-frame obtained through the inversion by the duration of the sub-frames, and multiplexing the result of the delaying and whichever of the positive sub-frame and the positive sub-frame obtained through the inversion is not the result of the delaying. The unipolar OFDM symbol frame can guarantee high power amplification efficiency and high transmission power efficiency, and is robust against a multi-path channel environment.

Abstract: A communications transceiver includes a baseband processor, a receiver section, and a transmitter section that includes a power amplifier. The receiver and transmitter sections communicatively couple to the baseband processor. In a calibration operation, the baseband processor produces a test signal to the transmitter section. Further, the baseband processor causes each of a plurality of power amplifier bias settings to be applied to the power amplifier. For each of the plurality of power amplifier bias settings, the power amplifier produces an amplified test signal, the receiver section couples back a portion of the amplified test signal to the baseband processor, and the baseband processor produces a characterization of the amplified test signal respective. Based upon a plurality of characterizations of the amplified test signal and respective power amplifier bias settings, the baseband processor determines power amplifier bias control settings.

Abstract: Methods and systems for level detector calibration are disclosed and may comprise calibrating a level detector integrated on-chip to eliminate an associated zero input offset voltage utilizing a replica bias circuit with no input ac voltage at the level detector or the replica bias circuit. The offset voltages of the level detector and the replica bias circuit may be combined to eliminate the associated zero input offset voltage of the level detector. The output signal may be generated by a difference of output signals from the level detector and the replica bias circuit. The level detector and the replica bias circuit may be biased utilizing a similar bias voltage. A plurality of known input voltages may be utilized to generate a corresponding plurality of output voltages of the level detector, generating a corrected transfer function that may be used to accurately set a transmitter power level.

Abstract: A novel sigma delta amplitude modulator having a noise transfer function adapted to shift quantization noise outside at least one frequency band of interest. In one embodiment, the sigma delta amplitude modulator includes a programmable order low pass stage. In a second embodiment, the sigma delta amplitude modulator incorporates comb filtering wherein each comb filter comprises a plurality of fingers to permit greater programmability in the frequency location of notches. A polar transmitter incorporating the sigma delta amplitude modulator is presented that shapes the spectral emissions of the digitally-controlled power amplifier such that they are significantly and sufficiently attenuated in one or more desired frequency bands.

Abstract: Methods and systems for level detector calibration are disclosed and may comprise calibrating a level detector integrated on-chip to eliminate an associated zero input offset voltage utilizing a replica bias circuit with no input ac voltage at the level detector or the replica bias circuit. The offset voltages of the level detector and the replica bias circuit may be combined to eliminate the associated zero input offset voltage of the level detector. The output signal may be generated by a difference of output signals from the level detector and the replica bias circuit. The level detector and the replica bias circuit may be biased utilizing a similar bias voltage. A plurality of known input voltages may be utilized to generate a corresponding plurality of output voltages of the level detector, generating a corrected transfer function that may be used to accurately set a transmitter power level.

Abstract: A transmitter for modulating an RF carrier signal with an input digital data stream is disclosed. The transmitter has a processor for generating digital phase and digital amplitude signals which characterise the input digital data stream, a signal generator for generating an RF carrier signal with a phase property defined by the generated digital phase signal, an amplifier arranged to receive the RF carrier signal as an input, and a bi-level switching circuit responsive to the generated digital amplitude signal to switch between the two levels to generate a voltage signal for supplying power to the amplifier.

Abstract: A digital signal offset adjusting apparatus has a capacitor causing an output terminal to pass a high frequency band of an input digital signal. A first coil has one end connected to an input terminal and a second coil has one end connected to an output. An operational amplifier has an input connected to another end of the first coil, a second input connected to a direct current voltage generator and an output connected to another end of the second coil. The operational amplifier outputs a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage. A frequency characteristic compensating circuit is connected between a reference point and the second input of the operational amplifier. The gain of the operational amplifier increases with a component having a higher frequency from among low frequency bands of the input digital signal.

Abstract: A modulator circuit comprises a negative impedance amplifier which is operable such that a signal applied to the amplifier is reflected and amplified. Switching means are provided for switching the impedance of the amplifier between two reflecting states such that the reflected and amplified signal is phase modulated. The impedances of the negative impedance amplifier are selected such that the phase of the reflected and amplified signal in the first reflecting state differs substantially from the phase of the reflected and amplified signal in a second reflecting state. For example, the phase switches by substantially 180 degrees. Preferably the impedances of the negative impedance amplifier in the two reflecting states are selected such that the reflection gain of the amplifier in the two reflecting states is substantially the same such that the reflected and amplified signal is a binary phase shift keyed.

Abstract: The disclosed embodiments include a wireless access system and method that enable the transmission of wireless access signals having a desired power level. In some embodiments, the wireless access system determines the amount of supply current drawn by certain devices and causes adjustment of the wireless access signal power level based on an assessment of the supply current.

Abstract: A communications transceiver includes a baseband processor, a receiver section, and a transmitter section that includes a power amplifier. The receiver and transmitter sections communicatively couple to the baseband processor. In a calibration operation, the baseband processor produces a test signal to the transmitter section. Further, the baseband processor causes each of a plurality of power amplifier bias settings to be applied to the power amplifier. For each of the plurality of power amplifier bias settings, the power amplifier produces an amplified test signal, the receiver section couples back a portion of the amplified test signal to the baseband processor, and the baseband processor produces a characterization of the amplified test signal respective. Based upon a plurality of characterizations of the amplified test signal and respective power amplifier bias settings, the baseband processor determines power amplifier bias control settings.

Abstract: The invention is directed to techniques for discovering a powerability condition of a computer network such as the existence of a remotely powerable device attached to a connecting medium of the computer network. Such detection can then control whether a remote power source (e.g., a data communications device such as a switch) provides remote power (e.g., phantom power) to the computer network. One arrangement of the invention is directed to an apparatus for discovering a powerability condition of a computer network. The apparatus includes a signal generator, a detector and a controller which is coupled to the signal generator and the detector. The controller configures the signal generator to provide a test signal to a connecting medium of the computer network, and configures the detector to measure a response signal from the connecting medium of the computer network.

Abstract: A transceiver circuit having 10 mb and 100 mb transmit and receive circuitries using the power saving methods allows for power consumption of the transceiver circuit to be significantly reduced. This is accomplished by providing each defined subcircuit with its own power supply and means of activation and deactivation. However, the method for activating and deactivating digital subcircuits and analog subcircuits are different and therefore different types of control signals and methods are provided. Furthermore, there are two general types of power-saving situations. The first type is near total circuit power-down and the second type is partial circuit power-down. In yet another embodiment, a method for minimizing energy usage during the idle period is utilized.

Abstract: A modulator circuit comprises a negative impedance amplifier which is operable such that a signal applied to the amplifier is reflected and amplified. Switching circuitry is provided for switching the impedance of the amplifier between two reflecting states such that the reflected and amplified signal is phase modulated. The impedances of the negative impedance amplifier are selected such that the phase of the reflected and amplified signal switches by substantially 180°. Preferably, the impedances of the negative impedance amplifier in the two reflecting states are selected such that the reflection gain of the amplifier in the two reflecting states is substantially the same such that the reflected and amplified signal is a binary phase shift keyed.

Abstract: A data transformation algorithm is selectively applied to each data vector as it enters the pipelined structure. In a selection step, the algorithm compares the bit value of the new data vector with the corresponding bit values of the preceding data vector, and sums the number of logic transitions. The transformation algorithm is applied to the new data vector only if it would reduce the resulting number of transitions, otherwise the data vector is propagated unmodified. Bit inversion is a data transformation algorithm according to the present invention that provides up to a 50% reduction in the number of logic transitions.

Abstract: Apparatuses and methods are disclosed for communications using current detection. According to one embodiment, a transmitter generates a signal on a transmission line by switching between two power sources. According to one embodiment, the transmitted signal is a balanced signal. Under an embodiment, a signal that has been transmitted on the transmission line is received by a receiver that includes a current detector, and the receiver detects the signal by sensing changes in current on the transmission line. According to one embodiment, the current detector includes a sensor that senses changes in the magnetic field generated by changes in current in the transmission line.

Abstract: The invention is a communication system having a series of output modules that provide continuous synchronization output signals. Each output module has a driver assembly has a driver output and a backup selector output that is capable of driving a failed next driver assembly. A sensor detects the failure of the driver output and generates a select signal in the failure state. A selector receives the driver output, a backup driver output, the select signal, and a select signal from the next driver assembly. The selector normally selects the driver output, but in response to a failure state from the select signal, isolates the failed driver output. The previous driver assembly transmits a backup selector output to the failed driver assembly to maintain a continuous driver output. The transformers are preferably placed on a separate card to reduce the thermal degradation of nearby electronics. As transformers rarely fail, replacing them when a card fails is wasteful.

Abstract: The pulse-shaping look-up table with transient suppression (530) avoids hard turn-on and turn-off transients by modifying word segments of initial and final digital words during transmission of a digital data sequence. A controller (570) sends a mode signal and a digital data sequence to the pulse-shaping look-up table with transient suppression (530). A mode buffer and command block (560) uses the mode signal to control the creation of initial and final digital words created by a data buffer and control block (550) from the digital data sequence. The digital words are used by a look-up table (540) to create a sampled digital output waveform sequence. The pulse-shaping look-up table with transient suppression (530) provides an accurate output waveform sequence with reduced spectral emissions even during start-up and shut-down of digital data transmissions.

Abstract: An RF modem used with a host device for transmitting information to, and receiving information from, other host devices. Prior to a transmission, the information is Manchester encoded and transmitted by On/Off Keying. A superregenerative receiver circuit (which may also operate as the transmitter) operating at the transmitted frequency detects the transmitted information. The information is recovered in conjunction with a timing function which times the buildup of RF energy within the receiver circuit so that a transmitted binary 1 can be distinguished from a binary 0. For use in a system with a plurality of hosts, multiple channels of operation are provided. In order to conserve power, the apparatus is operated in a power saving, sleep or scanning mode, as well as a full power active mode.

Abstract: The invention reduces transient peaks in signals transmitted in CDMA communication systems. A plurality of spread spectrum data signals are combined into a combined signal having fluctuating power level corresponding to the combination of the data signals. The combined signal is modulated to produce an RF signal for transmission. The average power of the combined signal is measured over a selected time period. The combined signal power level is adaptively limited to a calculated power level based at least in part on the measured power.

Abstract: A self testing wireless data communications system suitable for use with an alarm system, the transmitting element of the communications system is capable of transmitting at two different output power levels. If the message is a supervisory message, it is transmitted at a lower power level than an alarm message, in order to ensure that non-supervisory alarm messages are received with an adequate signal margin.

Abstract: In a portable telephone set having an audio-frequency amplifier (12) for amplifying a sound signal from a microphone (11) and a codec (13),for digitizing and coding the sound signal into a digital sound signal which is transmitted therefrom, a level of said sound signal is monitored (17) to produce a detected level and is averaged at a timing (18) and compared with level data stored in a memory (15), and an amplification control signal is produced. At least one of the audio-amplifier (12) and said codec (13) is controlled its amplification degree in response to the amplification control signal.

Abstract: In a burst signal transmitting apparatus for power-amplifying a burst signal to transmit the power-amplified burst signal, a correct transmission output can be obtained even in an initial burst signal after a power supply is turned ON. In this burst signal transmitting apparatus, a signal supply to a transmission antenna is blocked by a switch for a predetermined time period after the power supply is turned ON, but this signal is supplied to a dummy. During this time period, the initial burst signal is produced, and an automatic level control is carried out for this initial burst signal by way of an automatic level control loop constituted by a detector, an LPF, a differential amplifier, a reference voltage source, and a variable attenuator. Accordingly, the transmission level is converged to become constant. Thereafter, the burst signal is supplied to the transmission antenna by the switch, so that the operation is entered into the normal operation.

Abstract: A method and circuitry for improved output power level calibration/compensation/control is disclosed. A single RF detector diode is employed, to which a bias current is applied prior to applying a coupled amount of the transmitted radio frequency signal to be measured during a level calibration or automatic level control function. The initial (pre-RF) voltage out of the detector circuit is stored and later subtracted from the detector's output voltage after application of the RF signal. This results in a voltage proportional only to the detected RF signal, independent of any circuit-dependent voltages and variations due to environmental conditions such as temperature fluctuation, and allowing precise control of the output power levels.

Abstract: A system to alter the voltage supplied to the linear regulator of a pulsed transmitter in accordance with the temperature of the regulator, the minimum voltage required for a transmission and the specific aircraft installation requirements so as to reduce problems of heat dissipation in the regulator.

Abstract: A unique wireless transmission signal structure has a preamble at a first data rate and a data portion including the base band signal at a second, higher data rate. The signal is generated in a manner which ensures that the transmitted signal is "on" no more than one half the entire transmission time. A unique wireless transmitter generates the inventive transmission signal. A crystal oscillator drives both a signal generation circuit and a frequency generator. This provides accurate timing and allows the transmission signal to be not self-clocked. A unique wireless transmission receiver has adjustable pre-detection and post-detection filters. When the receiver is scanning for an incoming transmission signal, the pre-detection filter has a wide bandwidth to receive incoming transmission signals within a predictable range of variations due to inaccuracies in the transmitter and receiver. At this time, the post-detection filter has a narrow bandwidth to pass the low bit rate preamble data and reject noise.

Abstract: An information transmission system includes a base station with a base transmitter and a plurality of satellite stations. Each satellite station includes a satellite receiver for receiving a transmission from the base station and a satellite transmitter including a transmitter amplifier, the transmitter amplifier requiring a preparation period of time to prepare the transmitter amplifier for operation. The transmission of information between and satellite station and the base station occurs during a transmission portion of a selected time slot within a succession of time slots. The amplifier in each of the satellite stations is prepared for transmission during a preparation portion of a same time slot having a duration at least equal to the preparation period for the satellite station transmitters and occurring prior to the transmission portion of the selected time slot.

Abstract: Some mobile station cellular networks use either amplitude modulation or constant envelope modulation depending on the situation. The pulsed transmitter of the mobile station is switched on and off by a first control signal (TXP) and the output power envelope shaping of the pulse to be transmitted is controlled in the feedback loop by a second control signal (TXC). According to the invention the output power is controlled by a third control signal (TXCE) which in the amplitude modulation case switches off the feedback loop for the period of the information transfer and which at other times closes the feedback loop.

Abstract: An apparatus and method generates a shaped transition between the minimum and maximum output power levels of a transmitter (500). When the transmitter is turned on a stepped transition (415) is generated at the beginning (3) of the transition region (409) followed by a shaped transition (417) to the end (6) of the transition region (409). When the transmitter (500) is turned off a shaped transition region (417') is generated at the beginning (162) of the transition region (411) followed by a stepped transition (415') at the end (3) of the transition region (411). The stepped transition (415 or 415') is generated by adjusting a voltage controlled attenuator (545) and the bias of a power amplifier (545) in the transmitter (500). The shaped transition (417 or 417') is generated by processing transmitted information through finite impulse response filters (507 or 509) before or after the time slot permitted for transmitting information.

Abstract: A semiconductor diode is connected across the cathode-to-anode path of a magnetron and through a storage capacitor and collector resistor to a supply voltage for enabling charging of the capacitor. A control pulse causes a switching transistor to conduct to discharge the capacitor through its collector-to-emitter path, an emitter resistor, and the magnetron, for causing the latter to oscillate. A feedback signal representative of the difference between the magnetron output frequency and a reference frequency is applied to a linear amplifier transistor which conducts through the emitter resistor for controlling the current flow through the switching transistor and the operating frequency of the magnetron.