Abstract: An amplification unit contains two or more sets containing a plurality of amplification circuits, and amplifies power of an RF (Radio Frequency) signal. A combining unit contains two or more combiners corresponding to the two or more sets, combines RF signals output by the amplification circuits, and outputs a resultant RF signal. The amplification unit has one chassis storing each amplification circuit. The amplification unit and the combining unit have two or more connectors which are arranged transversely. The amplification unit and the combining unit are attachable/detachable.

Abstract: A power amplification device capable of detaching an element relating to the power amplification of an RF signal from an element relating to the combining of RF signals. The amplifying unit 1 is provided with a plurality of groups of amplifier circuits 2 that amplifies the power of a RF signal and the plurality of groups of amplifier circuits each includes a predetermined number of the amplifier circuits 2. A combining unit 5 includes a first combiner 7 and a second combiner 8. The first combiner 7 is provided in association with the group of the amplifier circuits 2, combines RF signals output from the amplifier circuits 2 belonging to the corresponding group, and outputs the RF signal after combining. The second combiner 8 combines the RF signals output from each first combiner 7 and outputs the RF signal after combining. Each first combiner 7 is a combiner usable for an RF signal in a specific frequency band. The amplifying unit 1 is attachable to and detachable from the combining unit 5.

Abstract: In one embodiment, a system and method for providing dynamic gain over non-noise electrocardiographic data with the aid of a digital computer are provided. A time series of a plurality of voltage values that comprises a digital representation of a raw electrocardiography (“ECG”) signal recorded by an ambulatory monitor recorder is obtained. One or more segments of the ECG signal is marked as noise, each of the segments including a plurality of the values, based on a difference between a maximum one and a minimum one of the values within that segment. Further segments not marked as noise are analyzed, each of the segments comprising a plurality of the values. A gain factor for all of the values in the analyzed further segments is determined based on the analysis.

Abstract: Methods and apparatus are disclosed for automatically adjusting antenna impedance match in a wireless transceiver employing phase-amplitude modulation. According to some embodiments of the invention, a wireless transceiver comprises a transmitter circuit and a receiver circuit connected to the antenna by a transmit/receive duplexer. An electronically adjustable matching network is located between the transmitter output and the antenna. To control the adjustable matching network, a directional coupler is located between the transmitter output and the matching network to separate transmit signals reflected from the antenna system, including the antenna, the matching network and the T/R duplexer. The reflected transmit signals are routed to the receiver circuit, which digitizes the reflected signal and determines an antenna reflection coefficient based on the digitized reflected signal and the modulation signal used to create the transmit signal.

Abstract: Embodiments for at least one method and apparatus of a wireless transceiver are disclosed. For one embodiment, the wireless transceiver includes a transmit chain, wherein the transmit chain includes a power amplifier. The wireless transceiver additionally includes a receiver chain that is tunable to receive wireless signals over at least one of multiple channels, wherein the multiple channels are predefined. Further, the wireless transceiver includes a voltage converter. The voltage converter provides a supply voltage to the power amplifier, and operates at a single switching frequency, wherein the single switching frequency and all harmonics of the single switching frequency fall outside of the multiple channels.

Abstract: A relaying device has a content signal input port configured to receive a first electrical signal conveying information, a content signal output port configured to emit a second electrical signal conveying the information and configured to receive a reference signal, a gain regulation circuit in electrical communication with the content signal input port to establish a predetermined gain upon receipt of the reference signal at the content signal output port and generate the second electrical signal by applying the predetermined gain to the first electrical signal, and a control circuit disposed in electrical communication with each of the gain regulation circuit and the content signal output port to receive and measure the reference signal to establish the predetermined gain.

Abstract: Methods and systems for processing a plurality of signals are disclosed herein. Aspects of the method may comprise amplifying an input signal. The amplified input signal may be bandpass filtered. Amplification of the input signal may be adjusted based on only narrowband received signal strength indication of the bandpass filtered amplified input signal. The amplified input signal may be downconverted and a blocker signal may be bandpass filtered from the amplified input signal. Signal strength of a desired signal from the amplified input signal may be measured. The amplification of the input signal may be adjusted utilizing a triple well (TW) NMOS transistor. A control signal may be generated based on the narrowband received signal strength indication of the bandpass filtered amplified input signal. The amplification of the input signal may be adjusted based on at least one of the generated control signals.

Abstract: A method for processing a plurality of signals may include amplifying an input signal and generating a wideband signal from the amplified input signal. The method may further include bandpass filtering the generated wideband signal to generate a narrowband signal, and adjusting amplification of the input signal based on a narrowband received signal strength indication of the generated narrowband signal, and/or a wideband received signal strength indication of the generated wideband signal. The amplified input signal may be downconverted to generate the wideband signal. The amplified input signal may be downconverted to an intermediate frequency (IF) and/or to a baseband signal to generate the wideband signal. At least one blocker signal may be bandpass filtered from the amplified input signal.

Abstract: An apparatus for automatically controlling a gain of a power amplifier includes a reception-signal detecting unit which detects a reception signal; a reference-voltage generating unit which generates a reference voltage; a gain control voltage detecting unit which compares the detected reception signal with the generated reference voltage to detect a gain control voltage; a gain control unit which controls a gain of an input signal to output a gain signal based on the detected gain control voltage; an impedance matching unit which compensates for mismatched impedance of the gain control unit according to gain control; and a power amplifying unit which amplifies the gain signal.

Abstract: A power amplifier having a phase shift and impedance transformation element is disclosed. The power amplifier comprises a plurality of amplification paths, a first phase shift element at an input of each amplification path and a second phase shift element at an output of each amplification path. The amplifier also comprises an impedance transformation element associated with the second phase shift element and a power combiner configured to combine an output of each amplification path into a single output.

Abstract: A gain control at the input monitors an input signal and a supply voltage, which drives an output. The gain control adjusts the gain to compress the input signal when the supply voltage decreases in magnitude and/or the input signal is of such magnitude to cause the supply voltage to decrease.

Abstract: A method and apparatus for maintaining approximately constant gain of an RF power amplifier includes a digital control module for modifying gain parameters of the power amplifier to provide a constant fixed power gain over the entire frequency range of operation. The digital control module compares stored frequency response parameters, which are indicative of the inherent closed-loop gain of the power amplifier, with the current selected gain and carrier frequency setting to generate a digital gain control value. The digital gain control value is used to modify a detected input RF envelope in the power amplifier analog loop. The modified input envelope is compared with an envelope of the transmitted RF signal to adjust the gain of the power amplifier. Optionally, the detected RF input envelope may be sampled to digitally compensate for variations in the RF input signal.

Abstract: The present invention relates to a power servo-loop in particular for controlling a power amplifier, the loop comprising a detection circuit (100) having coupling means (1) for taking off RF signals, and a detection unit (400) for delivering a detection signal (Vdet) partially representative of a first RF signal taken off by the coupling means. The detection circuit of the invention comprises, between the coupling means and the detection unit, detection control means (21, 22, 4) for substantially eliminating an “interfering” second RF signal also taken off by the coupling means, such that the detection signal is entirely representative of the first RF signal.

Abstract: A gain control at the input monitors an input signal and a supply voltage, which drives an output. The gain control adjusts the gain to compress the input signal when the supply voltage decreases in magnitude and/or the input signal is of such magnitude to cause the supply voltage to decrease.

Abstract: There is provided a distortion canceling circuit for reducing an unbalance between a higher and a lower 3rd order distortion at frequencies of (2·f2−f1) and (2·f1−f2), respectively, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components, i.e., f1 and f2. Phase modulation control means supply a control signal, which has a difference frequency of (f2−f1), to phase modulation means, the control signal being generated based on the amplified input signal outputted from the amplifier. The phase modulation means performs phase modulation on the amplified input signal based on the supplied control signal to thereby generate a higher and a lower side-band signal having frequencies of (2·f2−f1) and (2·f1−f2), respectively, each of which has an identical amplitude and a phase difference of 180° with respect to each other.

Abstract: The invention addresses the problem of obtaining ways and means for providing a compensational gain, which can be used for gain compensation in connection with power amplifiers (1) and other devices. According to the invention a power splitter (11) splits a signal into two components. A phase shifter (15) introduces a frequency dependent phase shift in one the components. Means (17, 19) are provided for introducing a change of amplitude in one of the components. A combiner (13) combines the components. By selecting appropriately the frequency dependent phase and the change of amplitude, a desired gain compensation characteristic is achieved.

Abstract: The variable power supply to an amplifier in an electrical circuit is dynamically controlled through the use of a lookup table responsive to one or more operating conditions of the electrical circuit. The lookup table is indexed by one or more of the operating conditions and the amount of amplification to be applied to an input signal to the amplifier is determined. One embodiment of the invention comprises a television transmitter circuit including a power amplifier circuit capable of amplifying a variable frequency COFDM or 8VSB input signal where the amount of amplification applied to the input signal is dynamically controlled through the use of a lookup table as a function of the frequency of the input signal.

Abstract: A distortion reduction system uses upstream signal information, such as the carrier frequencies in an input signal, to adjust at least one frequency for a pilot signal to be injected into the distortion reduction system and to be detected at the output of the distortion reduction system, thereby enabling improved distortion reduction of changing input signals. For example, processing circuitry obtains the traffic frequencies making up a signal to be amplified by a feed forward arrangement. Using the traffic frequencies, the processing circuitry determines at least one frequency for a pilot signal, and the processing circuitry tunes a pilot signal generator to the at least one frequency for the pilot signal. The feed forward arrangement receives the signal to be amplified and provides replicas of the signal on a main signal path and on a feed forward path. The pilot signal is injected into the main signal path at the at least one frequency along with the signal to be amplified.

Abstract: The present invention proposes a method for adjusting a parameter (IDQ) of a power device (1) by changing an input signal (VG) to said power device, said method comprising the steps of taking (S2) a sample of an output signal (POUT) of said power device (1), detecting (S5) at least a first and a second signal component level (P1ST, P2ND) of said sampled output signal (POUT), processing (S6) the at least detected first and second signal component level (P1ST, P2ND), deciding on the basis of a result obtained in said processing step (S6), whether a compensation of a change of said parameter (IDQ) is required, and if such a change is to be compensated, determining (S8) a changing value (V) for said input signal (VG) and adjusting (S9) the parameter (IDQ) by changing said input signal (VG) by said determined changing value (V). Furthermore, the present invention proposes a corresponding device.

Abstract: A power amplifier system for use in amplifying an RF input signal exhibiting a given operating frequency within a known range of frequencies. The system includes a signal modulator that receives and modifies the input signal and provides therefrom a modified first signal. A power amplifier receives and amplifies the modified first signal. A first power detector detects the input signal and provides therefrom an average input power signal representative of the average input power thereof. A second power detector connected to the output of the amplifier provides an output average power signal representative of the average output power thereof. A controller adjusts the magnitude of said average input power signal and the magnitude of said average output power signal as a function of the operating frequency. The controller compares the adjusted said input average power signal and said adjusted output average power signal and controls said modulator in accordance therewith.

Abstract: The variable power supply to an amplifier in an electrical circuit is dynamically controlled through the use of a lookup table responsive to one or more operating conditions of the electrical circuit. The lookup table is indexed by one or more of the operating conditions and the amount of amplification to be applied to an input signal to the amplifier is determined. One embodiment of the invention comprises a television transmitter circuit including a power amplifier circuit capable of amplifying a variable frequency COFDM or 8VSB input signal where the amount of amplification applied to the input signal is dynamically controlled through the use of a lookup table as a function of the frequency of the input signal.

Abstract: A power amplifier to process an input signal includes an amplifying device operating at a quiescent point and a bias network that varies the quiescent point according to a frequency of the input signal. In a variant of this power amplifier, the bias network includes a compensation circuit to provide a bias signal that varies according to a frequency of the input signal and a bias circuit to vary the quiescent point according to the bias signal. In an alternative embodiment of the invention, a method of making a power amplifier includes steps of measuring a gain performance of an amplifying device at a plurality of frequencies, determining a desired quiescent point of the amplifying device at each frequency of the plurality of frequencies, and constructing a bias network that varies an operating quiescent point of the amplifying device according to a frequency of the input signal so that the operating quiescent point approximates the desired quiescent point at each frequency of the plurality of frequencies.

Abstract: A power amplifier system for use in amplifying an RF input signal exhibiting a given operating frequency within a known range of frequencies. The system includes a signal modulator that receives and modifies the input signal and provides therefrom a modified first signal. A power amplifier receives and amplifies the modified first signal. A first power detector detects the input signal and provides therefrom an average input power signal representative of the average input power thereof. A second power detector connected to the output of the amplifier provides an output average power signal representative of the average output power thereof. A controller adjusts the magnitude of said average input power signal and the magnitude of said average output power signal as a function of the operating frequency. The controller compares the adjusted said input average power signal and said adjusted output average power signal and controls said modulator in accordance therewith.

Abstract: In an automatic gain control (AGC) circuit based on a peak detection system having two filters, a voltage comparator selects one of two voltages and compares the selected voltage with a detection signal output from a wave detector. A second AGC filter selects a cut-off frequency based on the result of comparison of the voltage comparator and supplies a signal resulting from low-pass filtering, based on the selected cut-off frequency, to a voltage-controlled amplifier as a control voltage. When a highly modulated signal is abruptly input, selection of the cut-off frequency of the second AGC filter occurs.

Abstract: A method and apparatus reduce the out-of-band frequency components of an RF amplified signal, preferably a CDMA signal, which has a carrier frequency which is not known in advance. The apparatus and method feature locating the frequency of the incoming signal by examining an RF output signal having both in-band frequency components and out-of-band frequency components. Typically the output signal is generated using a high-power, Class A/B amplifier. Once the frequency of the carrier has been determined, the out-of-band components are used to generate control signals which, in, for example, a feedback or feedforward circuitry, reduce the energy of the out-of-band signals and thereby provide a more linear amplifier transfer function.

Abstract: A high frequency amplifier circuit includes the voltage source supplying the power source voltage on the output side of the high frequency amplifying active element. The high frequency amplifier is constructed with a voltage detector detecting a difference frequency voltage of the input signal at a frequency lower than the input signal of the high frequency amplifier circuit and control portion for attenuating the difference frequency voltage from the output signal by controlling the power source voltage on the basis of the difference frequency voltage detected by the voltage detector. Therefore, distortion due to modulating the input signal with the difference frequency component of the input signal can be reduced.

Abstract: A circuit arrangement that reduces selected intermodulation. The circuit arrangement includes a signal amplifier coupled to a bandpass filter via an electrical path. Signal energy outside the passband is reflected back into the amplifier and causes intermodulation. The electrical path is constructed with a length that reduces intermodulation, where the length is an odd multiple of one-fourth the wavelength of a predetermined frequency in the passband. The length of the electrical path reduces intermodulation because certain signals reflected by the bandpass filter are approximately 180.degree., or an odd multiple thereof, out of phase. Energy of problematic signals that are near the edge of the passband or in the stopband is reduced, such as third order intermodulation product and pairs of signals that produce third order intermodulation products.

Abstract: An amplifier system for a radio receiver, comprising: amplifier means for amplifying a signal applied to an amplifier input to generate an amplifier output signal; and control means for sensing the amplifier output signal and, in response to a relatively high level of the output signal, controlling the current applied to the amplifier input to maintain the amplifier means in a linear mode of operation.

Abstract: A microprocessor detects input power and output power of a two transistor, Class AB amplifier, and provides an adapted bias level of the transistors which has been adapted from detected input power. The gain of the amplifier is maintained by the microprocessor depending upon the detected input power and frequency as well as detected output power.

Abstract: A musical instrument amplifier system (FIGS. 1 and 2) with a frequency selective crossover circuit (10) using passive band pass filters (36, 44) to separate the amplified signals from the power amplifier (14) of an amplifier system (12) into low frequency signals on an output connector (42) for a specially adapted bass audio speaker (38) while the higher frequency signals are applied to another speaker (46). The crossover circuit (10) is selectively connected with the normal speaker output (24) in lieu of the speaker (38) to add frequency crossover capability to any amplifier system. In another musical instrument amplifying system (88), the crossover circuit (FIG.

Abstract: A power amplifier (10) suitable for satellite cellular communication systems provides highly efficient linear amplification of noise-like RF signals that have multiple carriers spread over a large instantaneous bandwidth. The amount of distortion present in the output is detected (14, 16, 18) and a feedback signal is provided to control the bias point of the active devices. As drive levels increase, the increased harmonic distortion power detected causes the power amplifier bias to increase thus reducing distortion. The control circuit (20) continually re-biases the power amplifier (12) for maximum efficiency for a predetermined level of distortion. The control circuit (20) may be adjusted to maximize efficiency while maintaining an allowable distortion level over the entire dynamic range of the devices.

Abstract: In an amplifier, which amplifies high-frequency communication signals, there develops odd-order intermodulation products which, because of the identical frequency spacing of the channels, fall into directly adjacent useful channels. In order to keep these intermodulation products below an admissible level, the input of the main amplifier is preceded by an attenuator of adjustable attenuation. The output of the main amplifier is connected to the input of an auxiliary amplifier which has a broader pass band than the main amplifier and amplifies also second-order intermodulation products. The auxiliary amplifier is followed by a low-pass filter which allows those intermodulation products to pass but shuts off other frequency ranges. The second-order intermodulation products which were allowed to pass are rectified in a detector and are amplified in a control circuit the output of which determines the attenuation of the attenuator.

Abstract: A bus leveling system for automatically monitoring and maintaining the amplitude of a radio frequency (RF) signal carded on a bus. A two-stage variable gain amplifier (64) is connected in series with the bus. Each stage of the variable gain amplifier is constructed with a PIN diode (84, 86) in a feedback path of the stage. The amplification of the variable gain amplifier is varied by the injection of current into the feedback path to adjust the resistance of the PIN diodes. A control circuit having an RE detector (78) is provided to monitor and adjust the gain generated by the variable gain amplifier. Preferably, the control circuit and the variable gain amplifier are incorporated into an Application Specific Integrated Circuit (ASIC) (62). The RF detector is constructed of two Gilbert multipliers (202, 204) to minimize errors caused by operating condition changes, including variations in power supply voltage, temperature, or process.

Abstract: A voice processing apparatus, comprisingan input terminal to receive electrical voice signals;a controlled-gain amplifier to amplify the electrical voice signals in dependence on a control signal to provide an output signal at an output terminal; and a control means to generate the control signal from the electrical voice signals. Wherein the control means includes: a notch filter with a passband within the range 550 to 950 Hz to produce a bandwidth reduced version of the electrical voice signals; a comparator/trigger circuit to receive the bandwidth reduced version of the electrical voice signals and to generate a trigger signal when the signal level of the bandwidth reduced version exceeds a preselected threshold; and a control signal generator to receive the trigger signal and in response thereto generate a first control signal, and in the absence of the trigger signal to generate a second control signal.

Abstract: A wide-band amplifier for driving a capacitive load includes an amplifier of a complementary push-pull circuit receiving and amplifying an input signal to produce an output signal for driving the capacitive load, and a controller for controlling bias current of the amplifier in response to a detected output derived from a high frequency component in the output signal of the amplifier. The controller makes the bias current of the amplifier variable with frequency and amplitude of the input signal.

Abstract: In a borehole acoustic telemetry system for acoustically transmitting data over a pipe suspended in a borehole, the level of noise in the data stream is inherently high, making the use of precise frequencies advantageous to provide useful data. A first transmitter in the system operates at a precise frequency to transmit a signal over the pipe where it is received by a receive and retransmit circuit path. Components in the receive and retransmit section filter and amplify a data component of the signal and retransmit the data signal at a precise frequency. Crystal controlled oscillator clocks are operated in the system at a same frequency in the transmitter and receiver-retransmitter to insure precise frequency control of the system.

Abstract: A frequency region split type noise reducing apparatus, comprising a compressor and an expander; the compressor (or the expander) including a plurality of frequency region splitting filters for splitting the frequency range of the signal into a plurality of frequency regions, a plurality of level sensors for detecting the levels of the signals in the respective frequency regions split by the plurality of filters, a plurality of voltage controlled amlifiers responsive to the level detected outputs of the corresponding level sensors for linearly compressing (or expanding) in terms of a logarithmic scale the dynamic range of the signal, and an adder for adding the outputs as compressed by the voltage controlled amplifiers for providing a composite signal, and the expander (or the compressor) including an amplifier and a switch circuit for connecting the compressor (or expander) to the amplifier to form a negative feedback circuit, whereby the expander (or the compressor) is implemented by a negative feedback amp

Abstract: Apparatus for controlling the gains of a pair of gain-matched amplifiers includes means for applying to each amplifier a pilot tone in the form of an exponentially-decaying periodic signal. The apparatus also includes three control loops, one for comparing the output of one amplifier with a reference signal to derive an error signal used to control the amplifier gains when the pilot tone is absent, and a second for controlling the gains when the pilot tone is present. The third loop subtracts the outputs of the two amplifiers and uses the resulting error signal in conjunction with one or other of the signals from the other two loops to control the gain of one of the two amplifiers.

Abstract: Disclosed is a system for supervising the level of input applied to a level regulator using a pilot signal. According to the invention, an input level supervisory circuit is provided which utilizes a level adjusting variable element of the level regulator, or employs a particular variable element arranged to be driven by means of the control voltage for said level adjusting variable element simultaneously with the latter element and having characteristics equal thereto, and which has a transmission ratio in a reciprocal or inverse relationship to the alternating current transmission ratio of a main signal alternating current transmission line of the level regulator. The input level supervisory circuit is supplied with an input voltage or current from a direct current constant-voltage power source or a direct current constant-current power source to generate an output voltage by means of which supervision of the level of the pilot signal input to the level regulator is performed.

Abstract: Compandor apparatus including a compressor comprised of an operational amplifier having a plurality of gain controlling feedback paths that are respectively responsive to different portions of the input frequency spectrum, and an expandor comprised of an operational amplifier having a plurality of gain controlling circuits that are respectively responsive to different portions of the input frequency spectrum.

Abstract: An adaptive signal weighting filter for use in a compander performs a frequency response weighting function so that during the encoding process the spectral region of dominant signal energy of the program signal is preemphasized with respect to other spectral regions and during the decoding process the corresponding spectral regions of the encoded signal are deemphasized with respect to one another in a complementary manner.

Abstract: A broadband automatic gain control amplifier is described incorporating a plurality of gain control loops, each responsive to signal levels at the output of the amplifier at different frequencies for developing a control signal to correct the output signal level simultaneously at that frequency and at other frequencies. Each of the gain control loops providing unique gain-frequency characteristic with respect to the other gain control loops.