Abstract: A received low-frequency standard radio wave, which is an amplitude modulation signal, is converted to an intermediate frequency signal Sa, and is output to a detection circuit and an AGC circuit. The detection circuit and AGC circuit generates an RF control signal Sf1 and IF control signal Sf2 from the input intermediate frequency signal Sa, and controls an RF control circuit and IF control circuit by outputting the generated RF control signal Sf1 and IF control signal Sf2 to the RF control circuit and IF control circuit. By this a radio wave reception device can speed up AGC operation.

Abstract: The dual band bi-directional amplifier has only one amplifier chain having an uplink amplifier and a downlink amplifier, but can nonetheless amplify signals from two frequency bands in both an uplink and a downlink direction between two antennas. This is possible by using duplexers and circulators to separate signals to and from each antenna into the two bands. In particular, for each frequency band handled by the circuit, the dual band bi-directional amplifier has a duplexer set for separating the signals from one of the bands into the uplink and downlink direction. In the case of a dual band amplifier, there are two sets of duplexers, one for each band. By using duplexers and circulators to differentiate signals in different bands travelling in different directions, there is no need for additional amplifier chains, which increase the manufacturing costs.

Abstract: A wireless receiver for receiving a specific wireless signal. The wireless receiver comprises an antenna, a bandpass filter, a offset device, and a control device. The antenna receives a first wireless signal. The bandpass filter has a resonance frequency, for retrieving the specific wireless signal from the first wireless signal. The specific wireless signal cannot be retrieved if the resonance frequency deviates. The offset device is coupled to the bandpass filter, for offsetting a deviation of the resonance frequency. The control device drives the offset device when the specific wireless signal is not detected by the bandpass filter. A transmission system utilizing the wireless receiver is also disclosed.

Abstract: An amplitude modulation receiver including an antenna for receiving a signal and an input filter connected to the antenna. A variable gain amplifier is connected to the input filter and is responsive to a gain control signal. An A/D converter is connected to the variable gain amplifier and is responsive to a sampling signal and provides a sampled digital signal. A D/A converter receives a demodulated signal and provides an analog output signal. A controller receives and demodulates the sampled digital signal from the A/D converter, generates the gain control signal for the variable gain amplifier, generates the sampling signal for the A/D converter, and provides the demodulated signal to the D/A converter. The demodulation and generation of the gain control signal and the sampling signal are performed in software.

Abstract: In order to simplify the circuitry upon integration of a mobile radio receiver in a terminal for mobile communication, the invention proposes the use of a receiving section in which at least one component is also arranged to receive broadcast signals, steps being taken so as to ensure that the gap arising in the broadcast reception is masked at instants at which control information is received for the mobile communication.

Abstract: A radio frequency switching apparatus wherein a filter for a transmitter module passes a transmission frequency to an antenna in a transmission mode and isolates the antenna and the transmitter module from each other in a reception mode. The radio frequency switching apparatus comprises a filter connected between the transmitter module and the antenna for passing a transmitted signal from the transmitter module to the antenna in the transmission mode. The filter also acts to cut off a reception frequency in the reception mode. The switching apparatus further comprises a first switching device for isolating the transmitter module and the antenna from each other in the reception mode, and a second switching device for isolating the antenna and a receiver module from each other in the transmission mode. No separate 1/4 wavelength strip line is required, making the circuitry of the switching apparatus simpler and, thus, the size thereof smaller.

Abstract: An electronic circuit is provided. The electronic circuit includes a first port, a second port, a first path coupled between the first and second ports, and a second, alternative path coupled between the first and second ports. The electronic circuit also includes at least one tunable circuit element shared between the first and second, alternative paths. The first path includes a delay line with a length selected to match at least one characteristic of the first path with a corresponding characteristic of the second path within a selected tolerance.

Abstract: An equal gain composite beamforming technique which constrains that the power of the signal output by each antenna is the same, and is equal to the total power of the transmit signal divided by the number N of transmit antennas from which the signal is to be transmitted. By reducing output power requirements for each power amplifier, the silicon area of the power amplifiers are reduced by as much as N times (where N is equal to the number of transmit antennas) relative to a non-equal gain CBF.

Abstract: A telephone handset dynamically buffers a real-time audio signal. The handset includes a microphone and a speaker connected to a telephone network interface. A proximity sensor is located near the speaker of the handset. The proximity sensor is connected to a circuit for measuring a coupling between the handset and an ear of a user. A buffer continuously records the real-time audio signal. The recorded signal can than be played back after the handset is first removed from the ear of the user, and second re-applied with the ear of the user using a time-compressed audio signal, until the playback signal is resynchronized with the real-time audio signal.

Abstract: A wireless communications mobile station (10) includes at least one antenna (240) and a RF transceiver (210,220) containing a direct conversion receiver (1) coupled to the antenna. The direct conversion receiver contains a low noise amplifier (3) for amplifying a received RF signal and for outputting the amplified RF signal to a current switching down-conversion mixer (4). The down-conversion mixer has a first input node for receiving the amplified RF signal, a second input node for receiving a local oscillator (LO) signal for mixing with the amplified RF signal and an output node coupled to an input of an operational amplifier forming a low pass filter (5A). In accordance with an aspect of this invention the low pass filter has a low pass pole generated by a resistor R and a capacitor C coupled in parallel in a feedback path of the operational amplifier, where a low pass comer frequency of the low pass filter is inversely proportional to the product of R and C.

Abstract: A direct conversion transmitter comprising two local oscillators, an in-phase and quadrature modulating signal and in-phase and quadrature modulators, adds a leakage detector and corrective algorithm with one or more digital to analog converters to generate a corrective signal. The corrective signal corrects for, minimizes, and suppresses local oscillator carrier leakage into the transmitted signal. In accordance with the invention, direct up transmitter carrier leakage is automatically measured at regular intervals during the transmit cycle. A DC correction, or a correction waveform as a function of time, is input to both the “in-phase” and “quadrature” modulators at the baseband input. The two correction signals are tuned according to a minimization algorithm to achieve the lowest possible carrier component in the spectral output of the transmitter at its ambient operating conditions and present power output level.

Abstract: A plurality of fingers 12 separately demodulate reception signals of a plurality of paths transmitted from a plurality of terminals. A first rake combining unit 13a combines a plurality of demodulated signals corresponding to a first transmission terminal from among the signals demodulated by the fingers 12. A second rake combining unit 13b combines a plurality of demodulated signals corresponding to a second transmission terminal from among the signals demodulated by the fingers 12. A change-over switch 16a connects a finger 12-8 from among the fingers 12-1 to 12-32 to either of the first rake combining unit 13a and the second rake combining unit 13b in a switchable manner. Therefore, a plurality of users can use a single finger in a switchable manner.

Abstract: A HTS-based RF receiver includes a cryocooler and a cryogenic enclosure in thermal communication with the cryocooler. The cryogenic enclosure contains a HTS filter and a LNA therein. A first MEMS bypass switch is positioned between a RF input and the HTS filter, the first MEMS bypass switch operatively coupling the RF input to the HTS filter. A second MEMS bypass switch is positioned between the LNA and RF output, the second MEMS bypass switch operatively coupling the LNA to the RF output. A bypass pathway located within the cryogenic enclosure is connected between the first and second MEMS switches to bypass the HTS filter and LNA when an operating parameter of the RF receiver falls outside a pre-determined range.

Abstract: What is described here is a device for receiving digital signals. The device comprises at least one receiving antenna, a measuring means for determining parameters relevant for the signal quality and a digitizer. The digitizer is controlled on the basis of the parameters determined by the measuring means for optimization of the reception.

Abstract: A power distributing and synthesizing device which comprises first to third signal terminals, first and second transmission lines and a resistor. The first signal terminal is provided at the connection portion between one end of the first transmission line and one end of the second transmission line; the second signal terminal is provided at the other end of the first transmission line; and the third signal terminal is provided at the other end of the second transmission line. The resistor is connected between the second signal terminal and the third signal terminal. LC serial resonators each comprising an inductor and a capacitor are respectively connected between the first to third signal terminals and a ground.

Abstract: A radio receiver includes a device for decreasing the data rate of reception data in accordance with the channel frequency of the reception data, and a device for performing signal processing for the reception data whose data rate has been decreased.

Abstract: A three port structure for the down conversion demodulation of a digitally modulated RF signal is proposed, wherein no RF switches are provided. The three port structure (1) has a first input (2) for the RF signal to be down converted and a second input (3) for a RF signal originating from a local oscillator (8). An output (4) of the three port structure (1) is supplied to a power sensor unit (5). The RF signal from the local oscillator (8) is modulated (7) before it is supplied to the three port structure (1).

Abstract: A portable telephone set capable of recognizing a call during music replay is disclosed. This portable telephone set comprises talking means and music replay means, and posts a call when receiving the same during music replay by the music replay means. Thus, the call can be recognized during the music replay.

Abstract: Disclosed is a method for displaying signal strength bars in a wireless terminal device. In the first step, RSSI (Received Signal Strength Indicator) values of the wireless terminal device consecutively collected for a predetermined time T are analyzed, and C/I (Carrier to Interference) ratios consecutively calculated for the predetermined time T are analyzed. In the second step, the number of signal strength bars to be displayed on the wireless terminal device is determined based on the analysis result of the first step. In the third step, the determined number of signal strength bars is displayed on the wireless terminal device. The signal strength bars are displayed in consideration of peripheral interferences around a wireless terminal device, and thus users can see the telephone communication quality or data transfer speed more accurately.

Abstract: A bias filtering module with at least two capacitive levels satisfies both a settle time requirement and a filtering requirement using a voltage dependent filter module whose capacitance is a function of a voltage potential on the filtering circuitry output terminal. The final capacitance level is approximately three times larger than the initial capacitance level. MOS capacitors having a voltage dependent charge capacity within the bias filtering module are coupled between a plurality of bias lines and circuit common. In an alternate embodiment, a selectable first group of capacitors are switched into connection within the bias filtering module as a second group of capacitors approximately reach a fully charged state within a specified settle time to provide improved filtering.

Abstract: The wide bandwidth transceiver includes a receiver section, a transmitter section, and a local oscillation module. The receiver section includes a 1st receiver intermediate frequency (IF) stage, a receiver switch module, and a 2nd receiver IF stage. The 1st receiver IF stage is operably coupled to convert a 1st inbound radio frequency (RF) signal into a 1st inbound IF signal based on a 1st local oscillation of the local oscillation module. The receiver switch module passes either the 1st inbound IF signal or a 2nd inbound RF signal, which have similar carrier frequencies, to the 2nd receiver IF stage. The 2nd receiver IF stage receives the selected signal from the receiver switch module and based on a 2nd local oscillation converts the selected signal into a low intermediate frequency signal. The transmitter section includes a 1st transmitter intermediate frequency (IF) stage, a 2nd transmitter IF stage, a power amplifier and a transmitter switch module.

Abstract: Apparatus, method and article of manufacture are shown for linear signal modification. An input signal is modified by providing one or more non-linear current sources and regulating at least one of the one or more current sources to output a signal based on one or more of the input signal characteristics. The modification of the output signal includes both amplification and attenuation.

Abstract: Disclosed is an architecture and method for high speed transmission over a four-wire subscriber line. Each modem in the present invention includes a V.90 transmit section and a V.90 receive section. The V.90 transmit section is dedicated to transmitting data over one pair of a four-wire subscriber line, while the V.90 receive section is dedicated to receiving data over the other pair of the four-wire subscriber line. The present invention permits full-duplex transmission at 56 Kbps over a four-wire subscriber line.

Abstract: Provided are a wireless communication medium and a method for operating the wireless communication medium. The wireless communication medium includes an antenna, an analog signal processor, a digital signal processor, and a central processing unit & logic module. The antenna transmits and receives a signal to and from an external apparatus. The analog signal processor converts an analog signal received via the antenna to a digital signal, and converts a digital signal to be transmitted to the external apparatus to an analog signal and transmits the analog signal to the antenna.

Abstract: Integrated RF components in the radio frequency (RF) front end of a communication device where the RF front-end components perform the RF front-end functions 3-1, 3-2, . . . , 3-k, 3-k+1), 3-k+2) . . . , 3-K that represent any K number of RF functions useful in a communication device. Groups of the K functions, for example the functions 3-k, 3-k+1), 3-k+2)′, are integrated into a common integrated component. An antenna function for converting between radiated and electronic signals is integrated with a filter function for limiting signals within operating frequency bands to form a filtenna.

Abstract: Delay positions for a RAKE receiver are selected by searching a plurality of multi-paths to select a set of multi-path delays associated with the highest signal to interference ratios (SIRs) and/or power values while maintaining a minimum distance between the multi-path delays during a first time interval. Respective SIRs and/or power values associated with the respective multi-path delays are determined during a second time interval. The respective SIRs and/or power values are filtered based on the SIRs and/or power values obtained while searching the plurality of multi-paths during the first time interval and determining respective SIRs and/or power values for the multi-path delays during the second time interval. For each of the respective multi-path delays, the respective filtered SIR and/or power value associated with the respective multi-path delay is compared with the SIRs and/or power values associated with delays immediately adjacent to that multi-path delay.

Abstract: An object of the present invention is to provide a rake receiver and a receiving method for efficiently assigning paths to fingers in a CDMA mobile communication system. In the present invention, a correlation-value calculation section 2 calculates correlation values between spreading codes and reception signals input from an input terminal 1, at all timings at which rake reception is possible, and outputs the calculated correlation values to a delayed-profile creation section 3 and a difference-history creation section 6. The delayed-profile creation section 3 determines average correlation values and issues the values as a delayed profile to a path selection section 4.

Abstract: A subharmonic mixer and a method of downconverting a received radio frequency signal is described. The subharmonic mixer of the present invention uses two stacks of switching cores with high order symmetry to reduce unwanted harmonic generation and uses transistors to improve headroom.

Abstract: In a CDMA receiver and a CDMA receiving method according to the present invention, based on a channel estimation result from a despread pilot symbol, a despread data symbol and a data symbol delayed by one symbol time, which have been delayed by an amount of time equivalent to the channel estimation, are derotated and simultaneously demodulated. Further, in the CDMA receiver and the CDMA receiving method according to the present invention, a vector conversion is performed on the despread pilot symbol, vector converted pilot symbols are accumulatively added, and the channel estimation is performed based on a result of an accumulative addition of the pilot symbols corresponding to the number of the pilot symbols to be used in the channel estimation.

Abstract: A ladder SAW (surface acoustic wave) filter which includes a first SAW resonator disposed in a parallel arm and a second SAW resonator disposed in a series arm, has an inductor connected parallel to at least one of the first SAW resonator and the second SAW resonator. The frequency of a resonance point or an anti-resonance point of the at least one of the first SAW resonator and the second SAW resonator is adjusted by changing the inductance value of the inductor.

Abstract: A receiving module and a TDMA-system receiver are adapted to broadening of bands of received signals and low frequencies of intermediate frequency signals. These apparatuses can be made compact and contribute to cost reduction. The receiving module is constituted of a low-noise amplifier, a high frequency LC filter, a Gilbert-cell type mixer, and baluns. A signal received by an antenna is amplified by the low-noise amplifier and is passed through the LC filter. After that, the signal is mixed with a local oscillation signal by the Gilbert-cell type mixer to be converted into an intermediate frequency signal.

Abstract: A method is provided for fast acquisition in a wireless network. This method involves receiving a first wireless signal at a receiving device, sent from a transmitting device; determining a first transmitting clock phase of the transmitting device by performing first acquisition and tracking processes on the first wireless signal; storing the first transmitting clock phase in the receiving device; receiving a second wireless signal at a receiving device, sent from the transmitting device after the first wireless signal; and determining a second transmitting clock phase of the transmitting device by performing a second acquisition process on the second wireless signal using the first transmitting clock phase as starting phase data. By using the stored first transmitting clock phase information as a starting point for acquisition, the receiving device can perform a second acquisition process that is much faster than a blind acquisition.

Abstract: A path detector (105) detects multipath waves on a transmission line based on a plurality of despread signals corresponding to fixed directional beams. An adaptive beam forming section (106-1 to 106-L) forms an adaptive beam combined signal for each path, using a weight generated by an adaptive algorithm and the despread signals. An adder (107) combines the adaptive beam signals for all paths, and a data judging section (108) judges data included in the combined signal.

Abstract: Disclosed is a small-size receiver that exhibits high sensitivity when used with a plurality of frequencies or a plurality of radio communication systems. To provide a small-size, high-sensitivity, direct conversion receiver for use with a plurality of frequencies or a plurality of radio communication systems, the present invention has a high-frequency-input signal path for a low-noise amplifier optimized for use with various frequencies or radio communication systems. The high-frequency-input signal path includes at least one band-pass filter and its input and output matching circuits. A low-loss switching means is used to connect an optimum high-frequency-input signal path to the low-noise amplifier in accordance with a selected operation mode.

Abstract: The present invention relates to a reflective communication system that allows information from wireless communication devices, such as radio-frequency identification devices (RFID), to be reflectively communicated to a receiver in lieu of using a separate communication system. A transmitter transmits a communication signal, having a carrier frequency, to the wireless communication device to provide power. The wireless communication device modulates a data signal onto the communication signal to form a reflected data signal. The wireless communication device reflects the reflected data signal directly to the receiver. In this manner, the process of communicating information from a wireless communication device is accomplished in one communication system rather than two. If the receiver also directly receives the communication signal from the transmitter, the receiver can determine the location of the wireless communication device relative to the transmitters.

Abstract: A signal processing circuit arranged to be used in a frequency modulated signal receiver is disclosed which includes a complex filter 105-110 connected to analog to digital converter 112, the filter having first 105-108 and second 109,110 complex filter stages and a voltage limiter 108 disposed between the stages. The circuit is of particular applicability for use in a Bluetooth receiver.

Abstract: The present invention relates to a single semiconductor die having an integrated low noise amplifier, a radio frequency (RF) subsystem, and sampling circuitry for use in a GPS receiver. The low noise amplifier has electrical performance suitable to receive a GPS signal from a unity gain antenna, thereby eliminating the need for external gain or an active antenna. After being amplified, the GPS signal is processed by a RF subsystem such that the signal is filtered and downconverted to a baseband signal, and the baseband signal is digitized by the sampling circuitry.

Abstract: Peak detector 104 detects the first peak timing where the correlation value of the first synchronization channel is the greatest. SSCH identifier 108 identifies the second synchronization channels by adding the correlation values of the second synchronization channels at a number of timings, and detects the timing where the sum of the correlation values of the identified second synchronization channels is the largest as a second peak timing. Based on the first and second peak timings, timing controller 105 instructs SSCH identifier 108 on the timing to perform correlation calculation. Likewise, based on the first and second peak timings, frequency corrector 110 calculates the error in a frame time measured by a base station, and converts this into a frequency difference, and changes the frequency of an oscillator in RF receiver 102 in such a way that corrects the frequency difference.

Abstract: A radio receiver having an FM band tuner, an AM band tuner, a controller coupled to both said tuners, and a radio data (RD) decoder for providing radio data. The RD decoder is coupled for receiving radio data from at least one of the tuners which is tuned to a radio program. The RD decoder is coupled to the controller for switching the radio receiver from FM band to AM band or vice versa based on radio program frequency correspondence data included in the radio data. The radio receiver is advantageous since it allows for automated cross switching between different frequencies whereon a same radio program is broadcast. This is particularly advantageous if the radio receiver, such as placed in a car, leaves the broadcast coverage area. User intervention is thus obviated.

Abstract: An electronic tuner of the present invention is arranged such that between an input part of the amplifying circuit and the ground serially connected are a coil and a diode, and a capacitor is connected between the ground and a connecting part between the coil and the diode. The diode is brought into conduction when a voltage supplied from a VHF High control source is at High level, and the coil and input capacitance of the amplifying circuit makes up a gain correction circuit for improving a frequency characteristic of a received signal in a VHF High band. The diode is brought out of conduction when a voltage supplied from a VHF High control source is at Low level, and the coil and the capacitor makes up a trap circuit for improving a frequency characteristic of a received signal in a VHF Low band. This makes it possible to minimize price increase of the apparatus and to improve frequency characteristics in the VHF High band and VHF Low band.

Abstract: A communication system for the wireless transmission of information through a single antenna is disclosed. The communication system comprises a handset and one or more modules capable of being coupled to the handset. The handset processes baseband information signals being received and transmitted, and transmits and receives radio frequency (RF) information signals through its antenna. Each module is removably couplable to the handset for converting baseband information signals into RF information signals for transmission, and for converting received RF information signals into baseband information signals. Each removably couplable module is optimized to enable wireless communication in accordance with at least one communication standard when coupled to the handset. By coupling the appropriate module with the handset, wireless communication in a number of geographic locations may be achieved.

Abstract: In systems which transmit both GSM modulated and EDGE modulated signals, time of arrival estimations can be improved without requiring the detection of the type of modulation used on the received signal. In accordance with the present invention, a received signal is initially demodulated by a receiver in accordance with a first demodulation scheme. The demodulated signal is split into two copies. Taking into account the initial demodulation, one of the copies is demodulated in accordance with another demodulation scheme, thereby resulting in a first signal demodulated in accordance with the first demodulation scheme and a second signal demodulated in accordance with a second demodulation scheme. A training sequence is used to correlate the two signals which are then summed in a incoherent integration process. The result of the incoherent integration is used to estimate the time of arrival of the received signal.

Abstract: A receiver receives analog signals at radio frequency (RF), and the RF analog signals are converted into the digital domain. As such, the receiver does not require frequency conversion stage(s) prior to analog to digital conversion. For example, the receiver can comprise at least one antenna(s) which receives radio frequency (RF) analog signals at different frequency bands. The analog RF signals are provided to a single analog to digital (A/D) converter, and the A/D converter converts the analog RF signals at the different frequency bands into digital signals within the Nyquist bandwidth. By properly selecting the sampling rate of the A/D converter for the RF analog signals, the A/D converter can produce replicas of the different frequency bands of the analog signals in non-overlapping portions of the Nyquist bandwidth.

Abstract: The baseband receiver provides a baseband process operating on a receiver in a communication system, such as an 802.15.4 communication system. The baseband process digitizes a baseband signal, and uses less than the full resolution of the digitized data to perform an automatic gain control. In another aspect of the baseband receiver a data frame is detected using less than the full resolution of the digitized data, and without the need for prior synchronization. After a frame is detected, the baseband signal is correlated with reference signals from a set of predefined reference signals, and the reference signal with the best correlation is identified. By identifying the best correlating reference signal, the baseband process is able to identify a characteristic of the baseband signal.

Abstract: A radio modem includes a modem: a central processing unit (CPU) connected with the modem for digital data transmission therewith; a read-only-memory (ROM) connected with the CPU; a memory connected with the CPU; and a radio transceiver connected with the modem for receiving/transmitting radio waves and performing an analog signal transmission with the modem. The radio modem has Group ID (GID) and Sort ID functions, and automatically replies according to the order of the Sort ID after identifying the Group ID and confirming that it is necessary to reply.

Abstract: Method and system are disclosed for providing an improved linearity Gilbert mixer. The Gilbert mixer of the present invention includes a conventional mixer core coupled to a high linearity, multistage amplifier. The multistage amplifier includes two or more transistor stages connected together in a global feedback arrangement. The global feedback provides a greater loop gain for the amplifier than the local feedback arrangement, thereby increasing the linearity of the amplifier. In addition, having more than one transistor stage in the amplifier serves to increase the isolation of the RF input signal from the LO input signal. Furthermore, by providing parallel output stages in the multistage amplifier, several mixer cores may be driven from the same source while sharing the feedback mechanism.

Abstract: A high-frequency coupler for extracting a secondary signal representative of a main signal carried by a conductive line, comprising two series-associated, respectively high-pass and low-pass, filters, and the input of which is intended to be connected to said line while its output is intended to provide the secondary signal, the filters being sized so that the sum of their respective attenuations is substantially constant over the coupler passband, and so that their respective cut-off frequencies are in said passband.

Abstract: A radio includes a receiver circuit, a microprocessor, an input/output (I/O) port, at least one switch for configuring the I/O port, an audio amplifier coupled to the receiver circuit and to the I/O port, an audio frequency transducer coupled to the I/O port, and a power supply coupled to the I/O port, the receiver, the microprocessor, the at least one switch, and the audio amplifier. The at least one switch is coupled to the microprocessor. The audio frequency transducer is selectively coupled to the audio amplifier through the I/O port and the power supply is selectively coupled to the I/O port to permit activation of the audio frequency transducer by a signal coupled from the audio amplifier through the I/O port and to provide access to the power supply through the I/O port.

Abstract: Audio equipment and a method of controlling audio equipment are provided. The equipment comprises a switching power amplifier circuit and a controller controlling a switching frequency of the power amplifier circuit, and the controller varies the switching frequency of the power amplifier circuit in accordance with a receiving frequency in a case of receiving at least a medium-wave broadcast wave.

Abstract: A channel select filter circuit is disclosed using a current-mode transconductance-capacitor (gm-C) architecture, which is tuned by digitally controlled capacitor arrays. The main filter includes at least one transconductor-capacitor (gm-C) filter and a transresistance amplifier. A replica transconductor-capacitor (gm-C) filter and a phase detector are used to establish any phase shift in an input signal, and a state machine adjusts capacitor arrays in the the replica transconductor-capacitor (gm-C) filter and the at least one transconductor-capacitor (gm-C) filter in order to set a cut-off frequency of the channel select filter.