Abstract: The AGC threshold of electric intensity level is set by the signal processor portion 107 in response to the measured result of the error rate measuring circuit 109 that measures the error rate of the received signal, and the gain control operation of the gain control circuit 106 is caused to start when the electric field intensity detected by the field intensity detector 105 reaches the threshold of electric intensity level. Accordingly, the optimum AGC threshold of electric intensity level can be set to meet the radio wave situation in which the radio receiver, i.e., the receiving situation of the received signal and also the gain control of the gain controlling means can be achieved to optimize the signal quality of the received signal in the situation of either the IM characteristic or the electric field variation characteristic, e.g., under the environment of the strong electric field IM or the environment in which the electric field is changed strongly.

Abstract: A method for signal gain adjustment in a multi-port, digital distributed antenna system uses a sorter to sort received signals in ascending order according to their signal levels. A threshold comparator generates a dynamic range fair threshold that is updated as any remaining system dynamic range is distributed amongst the remaining signals. Any received signal that is less than or equal to the threshold is attenuated with a unity gain factor. A signal that is greater than the threshold is attenuated with a gain factor that is inversely proportional to the signal level.

Abstract: A method for controlling gain of an amplifier includes amplifying one or more received signals to produce one or more amplified signals. The method also includes generating a plurality of down converted signals using the one or more amplified signals. The method further includes amplifying the plurality of down converted signals based on a gain control signal. In addition, the method includes varying a time constant of the gain control signal based on a time derivative parameter associated with the plurality of down converted signals.

Abstract: In multi-path regions of high wave strength, noise in produced sounds of a vehicle audio system is reduced due to controlling of amplification of radio waves received by an on-glass antenna on the basis of wave strength at a running position of a vehicle and its change rate.

Abstract: A speed-up mode control system is operative to generate a speed-up mode signal based on a gain control signal from associated digital circuitry. The speed-up mode signal controls electronics associated with one or more amplifiers to facilitate settling time of an output signal of the amplifier(s) that occurs when the gain of the amplifier changes. The gain control signal also can be delayed to provide a delayed version of the gain control signal for controlling gain of the amplifier(s).

Abstract: The invention aims to minimize the analogue/digital converter over-dimensioning within the framework of reception of signals originating from a satellite and exhibiting power levels which can vary over time. The invention proposes a technique of automatic gain control which handles the setting of the noise level associated with the amplified signal. The automatic gain control is achieved by neutralizing the signal received by the antenna, and by adjusting the gain during the neutralization of the signal received until a predetermined noise level is obtained at the end of the reception facility. The invention also pertains to a device comprising the means for implementing the method.

Abstract: A transceiver front-end provides an interface between a transmission medium and transmitter, and between a transmission medium and receiver. The transceiver front-end includes a hybrid circuit, a high-pass filter, and a gain stage, that permits the reduction or the complete elimination of buffer amplifiers. Buffer amplifiers can be eliminated because the hybrid circuit and/or the high-pass filter are adapted so that they can be directly connected to each other, without a loss in circuit performance. Furthermore, the high-pass filter and/or the gain stage are also adapted so they can be directly connected. As such, the transceiver front-end can be constructed using all passive components, reducing or eliminating excess heat generation.

Abstract: A self-tuned millimeter wave transceiver module includes a microwave monolithic integrated circuit (MMIC) having at least one amplifier. A controller is operatively connected to the MMIC for sensing amplifier operating conditions and tuning the at least one amplifier to an optimum operating condition. The controller includes a surface mounted microcontroller chip operatively connected to the MMIC.

Abstract: A method of electronically tracking and locating a very large number of objects such as, but not limited to, personal case files in health care, law, or human services systems is described. Each object to be tracked has an attached miniature radio transmitter called a tag which sends a coded signal to a network of receiver base stations with limited but overlapping reception ranges. Each receiver base station places in its own memory the time at which a record enters its range, remains in range, and the time at which it leaves. The various receiver base stations are interconnected to a host computer. By polling the memories of each receiver base station, the computer is able to determine the current location of any record.

Abstract: A radio receiver portion of a transceiver includes a differential amplifier that is used to provide a fast response. A pair of input MOSFETs of the differential amplifier stage are coupled to an active load. A voltage follower circuit is coupled to each output stage of the two stage differential amplifier to drive a current through a load without reducing the output voltage. The voltage follower stages each include a current mirror that replicates current level defined by an input MOSFET of the voltage follower circuit and, by its configuration, a voltage level produced by the differential amplifier to the input MOSFET of the voltage follower circuit. Accordingly, the differential amplifier stage defines the amplification of the circuit while the voltage follower circuits replicate the amplified output with the ability to drive a load.

Abstract: An AM receiver includes an audio filter that is configured to selectively narrow the audio bandwidth of the demodulated signal when a signal with a low signal-to-noise ratio is received. By suitably bandpass-filtering the signal, for example, to 200–5000 Hertz, the intelligibility of the demodulated audio signal is not substantially reduced, whereas this bandpass-filtering substantially suppresses the audio noise that is typically found to be most annoying when listening to an full-bandwidth audio signal with a low signal-to-noise ratio. Optionally, the audio filter also provides gain to the bandpass-filtered signal.

Abstract: A filter module for reducing a DC offset voltage in a radio frequency communication channel is described. A first capacitor is coupled between a first differential input node and a first differential output node. A second capacitor is coupled between a second differential input node and a second differential output node. An active variable resistor is coupled between the first differential output node and the second differential output node. The active variable resistor receives a control signal. The control signal adjusts the value of the active variable resistor, which adjusts the frequency response of the filter module. The rate at which the filter module reduces DC offset voltages is thereby adjusted. The filter module is also adaptable to single-ended applications.

Abstract: An automatic gain control circuit with a very wide operational range, less hardware, and faster response, and more flexibility includes a signal strength estimator, a gain adjusting factor device and a multiplier. After the signal strength estimator finds signal strength, the gain adjusting factor device will generate a gain adjusting factor corresponding to the signal strength. Then the multiplier will update gain by multiplying it the gain adjusting factor.

Abstract: The radio receiver includes a low noise amplifier that amplifies a received signal to one of three different gain settings. One gain setting is maximum amplification, a second gain setting is 6 dB below maximum amplification and a third gain setting is 32 dB below maximum amplification. In the case of the third setting, the low noise amplifier actually attenuates the received signal by 6 dB. The radio receiver includes a pair of received signal strength indicators that provide received signal strength indications to logic circuitry. Responsive to the received signal strength indications, the logic circuitry generates control commands to the low noise amplifier to prompt it to amplify at one of the three specified levels. Generally, if the received signal has a gain level that exceeds a specified threshold, the low noise amplifier actually attenuates the received signal; otherwise, the level of amplification that is actually provided is a function of the presence of intermodulation interference.

Abstract: Apparatus, and an associated method, for a direct conversion receiver by which to selectably increase the sensitivity of the receiver. The direct conversion receiver includes a baseband amplifier positioned in front of a baseband filter, and coupled to receive a direct-converted baseband signal. The gain at which the baseband amplifier amplifies the signal provided thereto is selected, in combination with gains applied to other amplification elements of the direct conversion receiver to distribute the gain across the receive chain. When a signal received at the receiver includes a large interfering signal component, the gain of the baseband amplifier is reduced to lessen the possibility that the amplified signal become saturated. A gain controller controls the gain of the amplification elements.

Abstract: A wireless communications transceiver system and a variable gain mixer used in the wireless communications transceiver system. The differential mixed output signal of the variable gain mixer is a constant current signal. The gain of the mixer is set by selectively connecting into the input section circuit of the mixer a degeneration impedance. By maintaining the current of the mixed output signal constant, the linearity of the variable gain mixer is maintained constant and there are no changes in harmonic rejection.

Abstract: A communications device includes a frequency conversion circuit and a control circuit. An antenna receives a radio signal at a first frequency and converts it into a radio frequency (RF) signal of the first frequency. The frequency conversion circuit is associated with the antenna and configured to convert the RF signal into a first signal component and a second signal component. The first and second signal components occupy a baseband. The control circuit has first ports connected to the frequency conversion circuit to receive the first and second signal components and second ports connected to a processor circuit to output amplified first and second signal components, and separate channels for the first and second signal components existing between the first and second ports. Each channel comprises an amplifier and a feedback loop configured to control the amplifier as a function of a reference signal and a control signal derived from the RF signal.

Abstract: A soft limiter for a signal processor includes a variable-gain amplifier, and a threshold detector. The variable-gain amplifier includes a signal input for receiving an input signal, a signal output for providing an output signal representative of the input signal, and a gain control input for controlling a gain of the amplifier. The threshold detector is coupled to the gain control input, and includes a control input for receiving a control variable thereon. The threshold detector is configured to set the gain of the amplifier to a first gain value when the control variable exceeds a threshold value, and to set the gain to a second gain value different from the first gain value when the control variable is less than the threshold value.

Abstract: A power measurement element (106) measures (302) the wide-band received signal power of a receiver (102), and a wide-band AGC system (108) transfers (306) receiver gain control from an on-channel AGC system (110) to the wide-band AGC system, when the wide-band received signal power exceeds a pre-programmed threshold for longer than a pre-programmed delay time. The wide-band AGC system is arranged and programmed to decrease (308) a front-end gain of the receiver through a plurality of gain steps of a pre-programmed size (208) applied at a pre-programmed rate until the received wide-band signal power falls below the pre-programmed threshold.

Abstract: An automatic gain control circuit optimizes a follow-up performance of an automatic gain control loop to thus assure a good receiving operation. A generation timing or a generation period of a control signal GC is decided in response to a lapsed time in operation of the receiver device. For a predetermined rise period from a non-operated state to the steady operation state when a power supply is shifted from its OFF state to its ON state (power supply is turned ON) or at the time of intermittent receiving operation, the generation period of the control signal GC is set shorter than the generation period in a steady operation state so as to accelerate the response characteristic of the automatic gain control gain rather than the steady operation condition, and then switched to the generation period in the steady operation state after a predetermined time.

Abstract: A method and apparatus for signal gain adjustment within an RF integrated circuit (IC) include processing that begins by determining the signal strength of a received RF input signal with respect to a first signal strength scale to produce a signal strength indication. The processing continues by determining whether the signal strength indication exceeds a first high power threshold. If not, the receiver continues to process received RF signals without additional attenuation. If, however, the signal strength indication exceeds the first high power threshold, the received RF input signal is attenuated to produce an attenuated RF input signal. In addition, the first signal strength scale is shifted to produce a shifted signal strength scale. The processing continues by determining whether the signal strength of the attenuated RF input signal exceeds a high power threshold of the shifted signal strength scale or is below a low power threshold of the shifted signal strength scale.

Abstract: An object of the invention is to receive a weak signal with high sensitivity and reduce distortion and signal suppression when a strong interference signal exists. When a high-frequency signal received by an antenna is to be amplified by an antenna amplifier and when an interference wave of high field strength exists, a switch circuit is switched by an output switchover circuit from the output of an amplifier to a through-circuit. The through-circuit guides the high-frequency signal, directly to the output side without passing through the amplifier. When the switching operation of the switch circuit is performed based on low-frequency components which are highly correlated with distortion components due to intermodulation, the switching operation can be performed more adequately. Noises can be reduced by performing a smoothing process on the switching operation, and the use of an inverting amplifier can prevent occurrence of oscillation.

Abstract: A high frequency circuit capable of realizing a power amplifier with a wide dynamic range in which it is hard to degrade the power addition efficiency at low output is formed by using a high output amplifier cell block configured to amplify input signals at a time of high output power, in which a DC power source voltage is supplied in parallel to first amplifier cells that are connected in parallel AC-wise with respect to input/output signals, and a low output amplifier cell block configured to amplify input signals at a time of low output power, in which a DC power source voltage is supplied in series to second amplifier cells that are connected in parallel AC-wise with respect to input/output signals.

Abstract: In a code division multiple access wireless communication system having at least one base transceiver station and at least one mobile station having a mobile station receiver assembly configured to receive a coded signal having an information-bearing signal portion and an associated interfering signal portion from the base transceiver station, a method and apparatus for automatic gain control compensation in the mobile station receiver assembly, is disclosed. The method includes causing a gain adjustment to the coded signal by an AGC circuit in the mobile station receiver assembly to produce a post-AGC signal having a post-AGC interfering signal portion with an associated post-AGC interfering signal power level, and an associated gain error value. The method further includes compensating for the gain adjustment to the coded signal if the number of receiver fingers assigned to demodulate the coded signal is less than or equal to a predetermined number.

Abstract: A control interface scheme provides for communicating control information between integrated circuits (ICs) in a wireless communication chipset. A serial 3-wire bus is configured to communicate a series of control words assembled on a digital IC to an analog IC prior to a data portion of a frame used by the wireless communication chipset in communicating data. The control words include control settings for use by the analog IC during the data portion of the frame. The control settings, which are stored in registers on the analog IC, include gain settings for two receivers and a transmitter, as well as phase lock loop (PLL) control information and power management information. Several timing signals generated on the digital IC are used by the analog IC during the data portion of the frame to select among the registers to obtain the appropriate control settings at the appropriate times.

Abstract: In an AGC circuit for correcting a variation in received level by feeding back feedback data based on the difference between the average received level and a reference value in units of slots to an AGC amplifier, when the difference between the average received level and the reference value is equal to or more than a predetermined value, the value of the feedback data is set to be larger than a normal value.

Abstract: A novel and useful apparatus for and method of automatic gain control (AGC) using Kalman filtering and hysteresis. A nonlinear, time-variant loop filter such as a Kalman filter is employed in the feedback loop of an AGC circuit. The circuit is able to transition quickly and make fast adaptations to new levels of the input signal by use of a restart mechanism used to dynamically modify the gain of the loop filter thus enabling the AGC circuit to quickly adapt to changes in the signal level of the input. An AGC circuit incorporating a hysteresis circuit in the feedback loop is also disclosed.

Abstract: A receiver (9) for receiving a plurality of different signals at the same time, said receiver (9) comprising means for identifying at least one strongest signal of said plurality of different signals and means for attenuating said at least one strongest signal with respect to the other of said plurality of signals wherein the said attenuating means comprises hybrid means (140 and 160).

Abstract: A discrete low-noise amplifier designed to operate in a mobile wireless environment uses two cascaded GaAs FETs to achieve 25 dB gain and 0.9 dB noise figure at 2.5 GHz. Active bias control circuitry responsive to monitored amplifier output power automatically and continuously adjusts the drain-source currents, and the load lines, of the cascaded FETs to (i) maintain power consumption at 33 milliwatts in nominal small-signal conditions, and to (ii) provide an elevated input third-order intermodulation intercept point (IP3) and a reduced noise figure during the presence of jamming. A 15 dB improvement in the input IP3 is achieved in large-signal operation. Amplifier operation is supported by an a.c. power detector of enhanced sensitivity and responsiveness because of un-grounded operation.

Abstract: An automatic gain control circuit includes a power calculator for calculating power of a modulation wave supplied to a demodulator; a power comparator for comparing the power calculated by the power calculator with ideal power of a modulation scheme of the modulation signal; a first gain controller for carrying out gain control of a first AGC amplifier in response to an output of the power comparator; and a second gain controller for carrying out gain control of the second AGC amplifier in response to the output of the power comparator. The automatic gain control circuit can solve a problem of a conventional AGC circuit in that precision gain distribution cannot be achieved to the two AGC amplifiers because the two AGC amplifiers are controlled by a single control signal output from the automatic gain control circuit.

Abstract: A received signal strength indicator operating at low intermediate of zero intermediate frequency is provided. The received signal strength indicator forms absolute values from an in-phase signal component and a quadrature signal component of a low or zero intermediate frequency signal that represents a received radio frequency signal. The absolute values are added. Logarithmic signal processing is performed either before absolute signal forming or after adding. Finally, low pass filtering is performed.

Abstract: A mobile communication system having an AGC (Automatic Gain Control) function includes an apparatus for adaptively controlling an output level of a local oscillator to reduce nonlinear distortion which may occur when a high-power RF signal is received or when it is necessary to transmit a high-power transmission signal. When a high-power RF signal is applied to a first stage in a receiving stage, the apparatus prevents the signal input to a reception AGC loop from being distorted by decreasing an output level of the local oscillator, which is provided to a down-converter. Further, when the output signal of a transmission stage has a high power level, the apparatus decreases the output level of a transmission AGC amplifier and instead increases the output level of the local oscillator, which is input to an up-converter located in an IF stage, so that it is possible to obtain a nonlinear distortion-reduced signal while obtaining the same output level.

Abstract: Attenuation of received RF signals begins by determining signal strength of the received signal. The processing continues by determining whether the signal strength of the received signal exceeds a high power threshold. The high power threshold is set just below a power level at which the receiver would saturate (e.g., clip the received signals). Processing continues by enabling transmit mode of a transmit/receive switch while receiving the RF signal when the signal strength of the received signal exceeds the high power threshold. With the transmit/receive switch in the transmit mode while receiving an RF signal, the transmit/receive switch provides an attenuation of approximately 20 dBm.

Abstract: A reception apparatus and a reception processing method are proposed to improve a reception characteristic by compensating deterioration of transmission quality independently of the traveling speed of a terminal. When a transmission signal sent via a radio transmission path is received and data is demodulated by carrying out various kinds of reception processing on the received signal, the present invention can perform reception processing best suited to a radio transmission path whose state changes according to the traveling speed of the terminal itself by receiving traveling speed information from speed detection means for detecting the traveling speed of the terminal itself and controlling reception processing on the reception signal according to the traveling speed information.

Abstract: The present invention relates to an ambient field level monitor device for a radio mobile terminal, comprising a reception unit for receiving a radio signal arriving at the radio mobile terminal to output a reception signal originating from the received radio signal and further to output an ambient field level signal, a synchronization decision section for receiving the reception signal from the reception unit to judge whether or not the reception unit is in synchronism with the received radio signal, and a time constant variable type ambient field level monitoring unit for receiving the ambient field level signal from the reception unit.

Abstract: A method of electronically tracking and locating a very large number of objects such as, but not limited to, personal case files in health care, law, or human services systems is described. Each object to be tracked has an attached miniature radio transmitter called a tag which sends a coded signal to a network of receiver base stations with limited but overlapping reception ranges. Each receiver base station places in its own memory the time at which a record enters its range, remains in range, and the time at which it leaves. The various receiver base stations are interconnected to a host computer. By polling the memories of each receiver base station, the computer is able to determine the current location of any record.

Abstract: A circuit is formed to steer current in and out of an inductive load in a manner that enables an amplifier to provide a plurality of gain steps without modifying an LC time constant for the circuit and, therefore, without modifying the tuning or frequency of oscillation for the circuit. A first group of MOSFETs are coupled in parallel and define the circuit current flow. A second group of MOSFETs are coupled in parallel to each other and in series to an impedance device. A third group of MOSFETs coupled to steer current in and out of the impedance device to affect the output signal coupled to one end of the impedance device. The transistors in the second and third groups of MOSFETs are selectively activated to control the amount of current that goes through the impedance device.

Abstract: A mobile radio communication apparatus comprises a power amplifier (102) for power-amplifying a transmission signal (103) into an amplified transmission signal which is transmitted through an antenna (101). A high-sensitivity detector (105) high-sensitivity detects the amplified transmission signal. The high-sensitivity detection signal is limited by a diode (107) to a predetermined voltage to be produced as a first output voltage signal. A low-sensitivity detector (110) low-sensitivity detects the amplified transmission signal. A predetermined offset voltage is superposed on the low-sensitivity detection signal to be produced as a second output voltage signal. The first and the second output voltage signals are combined into a combined output signal. A comparator (118) compares the combined output signal with a transmission ramp production signal supplied from a mobile radio communication apparatus control section. With reference to a comparison result, a dynamic range of the power amplifier is controlled.

Abstract: A radio frequency receiver includes an amplifier and a detector that produces a bias control signal indicating the level of the signal environment in which the receiver is currently operating. A bias generator sets the bias level of the amplifier according to the bias control signal, where the bias level tends to increase as the signal level increases. Other circuits within the early stages or front end of a radio frequency receiver can also have such reactively adjusted bias levels. These include buffers for local intermediate frequency oscillators and radio frequency to intermediate frequency mixers or converters. The invention can be used to increase the range of linearity (and thus the intermodulation immunity) of RF amplification stages. It can also be used to reduce typical power consumption by reducing the bias level under typical conditions and relying on the bias control to increase bias levels under adverse signal conditions.

Abstract: A device for controlling a receiving amplifier in a radio terminal by monitoring the transmission/reception mode and varying the current to an amplifier that amplifies an output signal to vary the linearity of the amplifier according to a received signal strength indicator (RSSI) measured of the input signal and a measured input signal quality.

Abstract: An integrated detector circuit (20) includes first and second gain stages (GS1, GS2). The first gain stage has an input (82) that monitors a high frequency signal (VRFDET) for routing a first detection current (IS1) to a node (60). The second gain stage includes a first current source (PF1) that supplies a bias current (IMAX1) indicative of a predefined amplitude of the high frequency signal. An input of the second gain stage monitors the high frequency signal to route a portion of the bias current to the node as a second detection current (IS2), which is limited to the bias current when the high frequency signal is greater than the predefined amplitude to compensate for a nonlinearity in a transconductance of the second gain stage.

Abstract: The invention pertains to a method and an arrangement for linearizing a radio receiver (20). The invention is advantageously applied in the reception circuits of mobile stations. A receiver according to the invention monitors the signal strength on the receive channel and its neighboring channels. In addition, the receiver can determine the quality of the detected signal by calculating its bit error ratio or signal-to-noise ratio. In normal conditions, i.e. when the signal strength is satisfactory on the receive channel and normal on the neighboring channels, the supply currents of the front-end amplifiers (A1, A2) and at least the first mixer (M1) of the receiver are kept relatively small. If the signal strength on the receive channel goes below a predetermined value or, on a neighboring channel, exceeds a predetermined value, said supply currents are increased. This may happen also if the bit error ratio or signal-to-noise ratio reaches a predetermined limit.

Abstract: The invention relates to a method and an Automatic Gain Control (AGC) unit for automatically minimizing the impact of inter-cell interference and/or interference between co-existing systems. The AGC unit is located within a transceiver unit, the transceiver unit is located in a radio base station in a Code Division Multiple Access (CDMA) telecommunication system and the AGC unit is connected to a High Power Amplifier SPA) unit adapted to transmit radio signals to a mobile terminal and to a Low Noise Amplifier (LNA) unit adapted to receive radio signals from a mobile terminal, the High Power Amplifier (HPA) unit comprises means for automatically adoption of a maximum output power level adapted to the current inter-cell interference and/or interference between co-existing systems wherein the AGC unit comprises means for controlling the output power levels of the output signals of the HPA unit by an AGC unit by using estimated interference related parameters.

Abstract: The present invention reduces automatic gain control (AGC) transients using first and second AGC processing branches to receive a signal. A gain is selectively adjusted (if desired) in the one of the AGC processing branches during a first time period. However, a gain is not adjusted in the other AGC processing branch during that first time period. The signals generated by the first and second AGC processing branches are then diversity processed to generate a received signal. The diversity processing effectively reduces the effect of any AGC transient.

Abstract: The present invention relates to an ambient field level monitor device for a radio mobile terminal, comprising a reception unit for receiving a radio signal arriving at the radio mobile terminal to output a reception signal originating from the received radio signal and further to output an ambient field level signal, a synchronization decision section for receiving the reception signal from the reception unit to judge whether or not the reception unit is in synchronism with the received radio signal, and a time constant variable type ambient field level monitoring unit for receiving the ambient field level signal from the reception unit.

Abstract: A digital automatic gain control linearizer for controlling a variable gain control element for automatically controlling gain, using an analog signal obtained by converting input digital data includes a memory an average calculation unit. The memory outputs upper and lower limit data corresponding respectively to the upper and lower limits of a binary data range which can be expressed by a plurality of upper bits forming the digital data. The average calculation unit calculates the average of one and other data of the upper and lower limit data, and repeats average calculation a predetermined number of times using the calculated average at least one of the upper limit data and the lower limit data. Average calculation is repeated a number of times corresponding to the lower-bit value of the digital data except for the plurality of upper bits, and the variable gain control element is controlled in accordance with the average calculated by the average calculation unit.

Abstract: A receiver is adaptively calibrated by using a coherent reference signal. The reference signal is selected to be offset from a center frequency of the calibration signal such that the resultant product is offset from baseband by some small amount. The resultant product is used to determine a next value of the calibration parameters.

Abstract: A circuit for compensating temperature of an automatic gain control (AGC) circuit includes a low noise amplifier (LNA) for amplifying a received radio frequency A) signal, an attenuation control unit for generating an attenuation control signal by sensing the amplified RF signal, and a PIN diode attenuator for attenuating the RF signal inputted to the LNA by driving the PIN diode with an attenuation control signal. A temperature compensation unit for compensating an attenuation change amount of the PIN diode caused by the change of temperature compensates the voltage change between the PIN diodes by using an additional PIN diode having identical characteristic of temperature as the PIN diode of the PIN diode attenuator.

Abstract: A communications device includes a frequency conversion circuit and a control circuit. An antenna receives a radio signal at a first frequency and converts it into a radio frequency (RF) signal of the first frequency. The frequency conversion circuit is associated with the antenna and configured to convert the RF signal into a first signal component and a second signal component. The first and second signal components occupy a baseband. The control circuit has first ports connected to the frequency conversion circuit to receive the first and second signal components and second ports connected to a processor circuit to output amplified first and second signal components, and separate channels for the first and second signal components existing between the first and second ports. Each channel comprises an amplifier and a feedback loop configured to control the amplifier as a function of a reference signal and a control signal derived from the RF signal.

Abstract: A single-ended circuit, such as an LNA (300), in accordance with the present invention includes an input power matching circuit (310) and a bias circuit (305) connected to an output transistor (Qin) which provides the amplification. A degeneration inductance (Le) and load impedance (Lo) couple to the emitter and collector of the output transistor (Qin), respectively. The bias circuit (305) is configured to eliminate base shot-noise of the mirror transistor (Q1) which generates the amplification. The bias circuit (305) in accordance with the present invention also eliminates the noise of the bias resistor (Rx1) that is included within the bias circuit (305). Specifically, the bias circuit (305) includes a current reference source (Iref) and an emitter follower circuit (315) connected to a current mirror circuit (Q1, Q2, Rx2) that connects to a bias resistor (Rx1). This bias circuit (305) can be implemented in a wide-class of single-ended circuits.