Abstract: In an access control system, a method and system for power management. A method of power management in a wireless access control system includes monitoring usage of a transceiver in a remote access point in a wireless access control system, de-activating the transceiver when the transceiver is not in use, and re-activating the transceiver upon occurrence of a predefined event. Additionally, the method may include transmitting a warning signal when an energy level of a power supply associated with the transceiver is below a predetermined threshold. The method may further include locking the remote access point when an energy level of a power supply associated with the transceiver is below a predetermined threshold. The remote access point may be locked until the energy level is above the predetermined threshold.

Abstract: An FFT unit subjects a baseband signal to FFT operation. An IQ-to-phase conversion unit converts an in-phase component value and a quadrature component value of each of a plurality of signals on respective subcarriers subjected to FFT into a phase component value. A phase equalization unit generates a plurality of reference phase values, based on the phase component of each of the plurality of signals on the respective carriers. Further, the phase equalization unit rotates the phase components of the signals on the respective carriers, in accordance with the plurality of reference phase values. A phase correction unit estimates an error in the phase component value of each of the plurality of signals on the respective carriers, based on a phase component of a pilot signal. Further, the phase correction unit rotates the phase component value of each of the plurality of signals on the respective subcarriers for a second time.

Abstract: The invention relates to a device for frequency conversion, comprising exactly one multi-band mixer (3) with means for transferring a signal (2) that is applied to the signal input of said multi-band mixer (3) from said signal's source frequency band to one out of a plurality of target frequency sub-bands at a time, yielding a transferred signal (4) at the signal output of said multi-band mixer (3), wherein said plurality of target frequency sub-bands defines at least a first and a second target frequency band, and a bank of switchable Variable Gain Amplifiers (VGAs) (5-1, 5-2) for amplifying said transferred signal (4), wherein for each of said target frequency bands, one switchable VGA (5-1, 5-2) is provided that is adapted to said target frequency band and is connected to the signal output of said multi-band mixer (3). The invention also relates to a method for frequency conversion.

Abstract: A system and method is provided for determining a channel estimate utilizing partial channel estimates to provide an aggregated channel estimate. A partial channel estimate is determined upon receipt of a data burst, such that a different subset of the channel estimate is updated every data burst. As a result, Fast Fourier Transform computations can be reduced by determining a portion of the channel estimate each data burst as opposed to determining a full channel estimate every data burst.

Abstract: The radio-frequency signal frequency conversion device generates intermediate complex signals (IF) for a correlation stage of a low power RF receiver. In order to do this, the device includes a first selective pass-band filter for filtering radio-frequency signals picked up by an antenna. A frequency synthesizer generates first and second high frequency signals, wherein the frequency of the first signals is higher than the frequency of the second signals. This synthesizer receives reference signals from an oscillator unit. A first mixer unit mixes the radio-frequency signals with the first signals in order to generate frequency-converted signals. A second pass-band filter filters the signals from the first mixer unit, and provides signals to a second mixer unit to mix them with the second high frequency signals. Finally, shaping means for the signals provided by the second mixer unit generate the intermediate signals.

Abstract: An embodiment is a receiver for a communications system that may substantially block unwanted signals in a frequency range to protect the receiver from overload. Simultaneously, the receiver of an embodiment substantially passes a desired signal so that its information may be processed by the, for example, communications system of which the receiver is part.

Abstract: The invention relates to a mixer circuit comprising an input node for receiving an input signal, a first output node 202, and a second output node 203, voltage to current conversion means and switching means operatively coupled to each other and to the input node, the first output node and the second output node to generate a mixed input signal at the first output node and the second output node in response to an oscillator signal. In an embodiment the voltage to current conversion means comprises a first and a second voltage to current converter, implemented as N-MOSFETs M2 and M3, with their gates connected to the input node. The drain of M2 is connected to the first output node 202, while the drain of the M3 is connected to the second output node M3. The source of M2 is connected to the switching node 221, while the source of M3 is connected to the second switching node 222.

Abstract: An AM radio receiver comprises an RF amplifier, a first mixer that converts the RF signal to a first intermediate-frequency signal, a first bandpass filter that band-limits the first intermediate-frequency signal, a second mixer that converts the output from the first bandpass filter to a second intermediate-frequency signal, a second bandpass filter that band-limits the second intermediate-frequency signal, an intermediate-frequency amplifier that amplifies the output from the second bandpass filter, an AM detector that demodulates the output from the intermediate-frequency amplifier and provides output of an audio signal, and a noise detector for detecting and eliminating ambient noise. The noise detector comprises a first noise detector that detects noise from the RF signal and eliminates the noise contained in the first intermediate-frequency signal, and a second noise detector that detects noise from the second intermediate-frequency signal and eliminates that noise.

Abstract: An architecture for a receiver front end utilizes a dual output low noise amplifier (102) driving separate, fixed preselectors (104, 106) coupled to a transformer (108) to generate a single ended output (113). A pair of blocks coupled in series provides a dual band output. Additional pairs of blocks (201, 203) can be cascaded in parallel to provide additional frequency bands of operation. The front end architecture of the present invention provides switchless multi-band operation to a communication device.

Abstract: Embodiments of wireless device and method for communicating in a wireless network are generally described herein. Other embodiments may be described and claimed. In some embodiments, a wireless device establishes a link using a directional antenna in an initially selected direction with another wireless device. If the link in the initially selected direction deteriorates, the link may be reestablished in a previously identified alternate direction. In some embodiments, the initially selected direction and the alternate direction are jointly selected by both the first and second wireless devices.

Abstract: An adaptive wireless receiver and method thereof is disclosed in the present invention. The receiver includes an antenna, a bandpass filter, a front-end unit and a demodulator. Elements inside the front-end unit can be reused when the receiver operates in a zero intermediate frequency (ZIF) mode and in a low intermediate frequency (LIF) mode. The front-end unit includes a first and second down-conversion mixer, an analog filter, a first and second analog-to-digital converter (ADC), and a digital filter.

Abstract: A radio frequency (“RF”) circuit configured in accordance with an embodiment of the invention is fabricated on a substrate using integrated passive device (“IPD”) process technology. The RF circuit includes at least one RF signal line section and an integrated RF coupler located proximate to the RF signal line section. The integrated RF coupler, its output and grounding contact pads, and its matching network are fabricated on the same substrate using the same IPD process technology. The integrated RF coupler provides efficient and reproducible RF coupling without increasing the die footprint of the RF circuit.

Abstract: A direct conversion method is disclosed. The method comprises: amplifying the input signal to generate an amplified signal; down-converting the amplified signal into two intermediate signals using a first set of ternary signals and a second set of ternary signals, respectively; filtering the first intermediate signal to generate a third intermediate signal; filtering the second intermediate signal to generate a fourth intermediate signal; digitizing the third intermediate signal into a first output signal in accordance with a first clock; digitizing the fourth intermediate signal into a second output signal in accordance with the first clock; and generating the first set of ternary signals and the second set of ternary signals based on a second clock.

Abstract: An integrated circuit comprises a switching transistor having an emitter connected to a grounding terminal, a first resistor connected between a first gate of a first field-effect transistor and the grounding terminal, a second resistor connected between the first gate of the field-effect transistor and a collector of the switching transistor, and a third resistor connected between the collector of the switching transistor and a drain of the field-effect transistor. The integrated circuit further comprises a bias voltage terminal connected to the collector of the switching transistor to apply a voltage to the bias voltage terminal from the outside of the integrated circuit via a sixth resistor.

Abstract: The invention relates to a direct conversion receiver for down-converting a received multi-carrier signal comprising at least a first and a second carrier signal at image carrier frequencies to a base band resulting in that the first carrier signal includes an image signal of said second carrier signal. Further, the known direct conversion receiver comprises at least a first and a second digital down-converter unit for separating the first and the second carrier signal from the down-converted multi-carrier signal after digitization. In order to make such receivers less complex and adjust them for fast time varying szenarios it is proposed to provide an error estimating unit to said receivers for calculating a compensating coefficient representing the quota and/or the phase position of the image signal of the second carrier signal being included in the first carrier signal and to remove the undesired image signal in response to said compensating coefficient.

Abstract: A phase alternating mixer is implemented by common-base differential transistor pairs, with two cross-coupled pairs providing a switching mixer function with harmonic gating suppression of harmonic responses to the switching mixing by control of local oscillator signals controlling switching of the differential transistor pairs. Rather than a resistive load, a switched capacitance load and integrating capacitors are connected to the output of the differential transistor pairs to provide first order low pass filtering of the double sideband output from the differential pairs, with a controlled bandwidth. Channel select switches demultiplex the double sideband signal into a baseband signal.

Abstract: A direct conversion satellite tuner is fully integrated on a common substrate. The integrated tuner receives an RF signal having a plurality of channels and down-converts a selected channel directly to baseband for further processing. The integrated tuner includes on-chip local oscillator generation, tunable baseband filters, and DC Offset cancellation. The integrated tuner can be implemented in a completely differential I/Q configuration for improved electrical performance. The entire direct conversion satellite tuner can be fabricated on a single semiconductor substrate using standard CMOS processing, with minimal off-chip components. The tuner configuration described herein is not limited to processing TV signals, and can be utilized to down-convert other RF signals to an IF frequency or baseband.

Abstract: A wireless communication system includes: a filter; and a semiconductor chip including a signal processing integrated circuit having an amplifier, wherein a main surface of the semiconductor chip is provided with a plurality of electrode terminals along an edge portion thereof; wherein the amplifier has a transistor including a control electrode, a first electrode through which a signal is outputted, and a second electrode to which a voltage is applied; wherein the control electrode, the first electrode and the second electrode of the transistor are connected to the electrode terminals, respectively; and wherein none of wirings are arranged between the electrode terminals and placements of the control electrode, the first electrode and the second electrode, making space between the electrodes and the electrode terminals narrow.

Abstract: The uplink transmission timing from a mobile communications device is defined with reference to the downlink reception timing of signals from a particular reference cell. When that reference cell is removed from the active set, there is defined a virtual reference cell, the timing of which is defined with reference to one or more of the cells remaining in the active set, such that the timing of this new virtual reference cell corresponds to the timing of the previous reference cell. The timing of the uplink transmission from the user equipment are then defined with reference to the new virtual reference cell, in the conventional way. This has the advantage that, following a soft handover, it is not necessary to adjust the timing of uplink transmissions from the user equipment.

Abstract: An electric circuit suitable for use as a radio receiver or part of a radio receiver, the electric circuit comprising amplification means, frequency mixer means, and filter means, wherein the frequency mixer mans is configurable to down-convert a wanted component of the amplified input signal to one of at least two intermediate frequency bands, and the filter means is dynamically reconfigurable between a first filter configuration which provides a first operating mode, and a second filter configuration which provides a second operating mode.

Abstract: A multi-stage amplifier assembly configured to receive a terrestrial digital television (“DTV”) input signal including multiple frequency channels. The amplifier assembly optionally includes a PIN diode coupled across differential inputs to a first stage of the multi-stage amplifier assembly. The PIN diode is controlled to attenuate the input when an exceptionally large signal is present in a channel adjacent to a desired channel. The PIN diode, essentially a variable resistor, permits the multi-stage amplifier assembly to maintain dynamic range in such situations for reasonable tradeoffs. The amplifier assembly further optionally includes an out-of-band second stage LNA. The amplifier assembly further optionally includes a multi-band input filter. The multi-band filer insures that the AGC operates on the TV band of interest, thus improving the linearity of the system. The invention can be implemented in CMOS and/or SiGe.

Abstract: In one embodiment, a method is provided of communicating in a wireless communication system. The method comprises (a) setting a decrement burst variable to be equal to a predetermined number representing a number of bursts of data from which to prematurely decode a USF codeword, (b) receiving a received burst of data comprising USF related data related to a portion of a USF codeword, (c) extracting said USF related data from said equalized received burst of data, (d) determining if a burst number variable is equal to said decrement burst variable, (e) incrementing said burst number variable and repeating (b) through (d) if said burst number variable is not equal to said decrement burst variable, and (f) decoding said USF codeword if said burst number variable is equal to said decrement burst variable.

Abstract: First and second transmission paths are provided between a first port to which an antenna is connected and a second port to which a transceiving circuit is connected. First to fourth reception filters, an amplifier circuit, and first to fourth hybrid circuits are provided on the first transmission path. A reception signal from the antenna is transmitted from the first port to the second port via the first hybrid circuit, the first and second reception filters, the second hybrid circuit, the amplifier circuit, the third hybrid circuit, the third and fourth reception filters, and the fourth hybrid circuit in this order. This reception signal does not return to the amplifier circuit, whereby the reception signal is prevented from oscillating due to positive feedback.

Abstract: The present invention relates to a balanced circuit arrangement and methods for linearizing and calibrating such a circuit arrangement, wherein linearization is obtained by introducing a load imbalance between the output branches of the balanced circuit arrangement. Thus, a controllable extraneous imbalance is created between the output loads of the balanced circuit arrangement to thereby obtain a linearization by means of even-order non-linearity.

Abstract: A receiver includes a processor and an RF bridge. The RF bridge is coupled to the processor to receive a reference signal from the processor. The RF bridge includes first and second frequency converters coupled to respective first and second antennas. The RF bridge also includes a third frequency converter coupled to outputs of the first and second frequency converters. In an alternative receiver the processor is coupled to receive an information signal from the RF bridge. The processor includes a digital frequency source to generate the reference signal based on a signal from a clock source and circuitry to detect a frequency difference from the information signal based on the signal from the clock source. In a variant, the circuitry to detect includes a first Fourier transformer having a first center frequency and a second Fourier transformer having a second center frequency different than the first center frequency.

Abstract: The present invention a method and apparatus for implementing a short range radio on a single chip. A radio, baseband, and link controller may be fully integrated within a single-chip comprising an area approximately one square centimeter. Through the integration of components upon a single package, cost and real estate savings may be provided in a baseband controller with improved performance.

Abstract: A high impedance circuit of the present invention includes an LC parallel resonance circuit for raising circuit impedance, and a diode, which is connected in parallel to the LC parallel resonance circuit, causing a loop current to flow back via the diode and an inductor in the LC parallel resonance circuit so that a counter electromotive force, due to a surge voltage, which occurs across the inductor is cancelled. A low noise block downconverter which includes a high impedance circuit having a high impedance prevents peripheral circuits from being destroyed by a counter electromotive force, due to a surge voltage, which occurs across the inductor. For this, a diode is provided to cause a loop current to flow back via the diode and the inductor so that the counter electromotive force is cancelled.

Abstract: By using ICs with combined inputs for the VHF-high bandpass circuit and the UHF bandpass circuit, undesirable resonances occur which are caused by one of the tuned circuits. The problem is solved by providing a switching means for decoupling the UHF bandpass circuit from the combined inputs when a VHF-high band signal is received by the VHF-high bandpass circuit. The switching means comprises a switch coupled between the UHF bandpass circuit and the common inputs.

Abstract: A start signal output circuit having an RF/DC conversion circuit to which radio frequency power (RF) of specified frequency is inputted and from which a direct current potential (DC) is outputted, comprises a detection/amplification circuit 210 which includes a voltage doubler wave-detector circuit 10 configured including a sensing diode Q1 (Tr34) for sensing the RF power, a differential amplifier including differential pair transistors Tr31 and Tr32, and a current mirror circuit. A base current of one Tr31 of the differential pair transistors is brought into substantial agreement with a DC component of a current flowing through the sensing diode Q1 (Tr34). A total of currents flowing through the differential pair transistors Tr31 and Tr32 is regulated to a substantially constant value by the current mirror circuit. Thus, the start signal output circuit which is small in size, high in sensitivity and low in power consumption can be realized.

Abstract: Apparatus and methods for reducing radio frequency interference produced by switching amplifiers, includes a variable-order noise shaper in a system that includes an AM tuner. An alternative implementation involves determining the tuned frequency of a radio signal. A first sampling rate is provided at which the radio signal is to be sampled. The first sampling rate is associated with a plurality of first harmonic frequencies. A second sampling rate is also provided and is associated with a plurality of second harmonic frequencies different than the first harmonic frequencies. The method involves selectively sampling the radio signal at one of the first and second sampling rates, wherein the first sampling rate is selected when the first harmonic frequencies do not coincide with the tuned frequency, and the second sampling rate is selected when the second harmonic frequencies do not coincide with the tuned frequency.

Abstract: A conventional receiver system has a filter circuit with unsatisfactory gain characteristics, and thus does not offer satisfactory reception performance. A receiver system of the invention has a filter circuit employing an equivalent inductor circuit including a capacitor, a gyrator composed of a plurality of operational transconductance amplifiers and having the capacitor as a load, and a resistor connected in series with the capacitor. A conventional receiver system has a band-pass filter circuit with a low third-order input intercept point, and thus does not offer satisfactory reception performance.

Abstract: An antenna detection and diagnostic system and associated method, including current and voltage detection circuits, are disclosed for detecting antenna failure mechanisms for integrated radio receivers. Integrated current limit detection circuitry is disclosed that determines current levels drawn by a remotely mounted antenna and generates a drive signal that controls a current limiting pass transistor such that current flow through the transistor is reduced when the detected current level drawn antenna rises above a current limit level. Integrated current and voltage detection circuitry is disclosed that detects current and voltage levels drawn by a remotely mounted antenna and determines under-current, over-current, and over-voltage antenna error conditions. At least one antenna error output pin for the integrated radio receiver is then used provide an output signal indicative of antenna error conditions.

Abstract: When a determination section of a reception apparatus determines that a control channel is intended for the reception apparatus, a comparing section of the reception apparatus compares control information transmitted on the control channel with a reception capability of the reception apparatus. A data channel reception section of the reception apparatus receives a data channel when the control information is within the reception capability of the reception apparatus, but does not receive the data channel when the control information exceeds the reception capability of the reception apparatus. When the control information exceeds the reception capability of the reception apparatus, the transmission section does not transmit an ACK signal and a NACK signal with respect to the data channel.

Abstract: A circuit for frequency translating a radio frequency signal comprises a plurality of mixer stages, each stage associated with a particular range of frequencies of a radio frequency signal. The circuit further comprises a switching circuit that communicates the radio frequency signal to a selected one of the plurality of mixer stages in response to a control signal. The selected mixer stage comprises a phase generation circuit that generates a plurality of phase signals, and at least one mixer that combines the radio frequency signal with one of the plurality of phase signals to generate at least a portion of an intermediate frequency signal.

Abstract: Precision in adjustment of filtering characteristics of a high frequency device is improved by providing a high frequency device comprising a first filter, a frequency converter, and a second filter. The high frequency device comprises a high frequency filter for extracting signal components in a predetermined frequency band from an input signal; a frequency converter for converting frequency of the signal components extracted by the high frequency filter; and an intermediate frequency filter for extracting signal components in a predetermined frequency band from the signal components, the frequency of which is converted by the frequency converter. The high frequency device further comprises a bypass circuit provided in parallel to the intermediate frequency filter downstream of the high frequency filter; and a switching mechanism including a switching circuit for switching connection of a signal path downstream of the high frequency filter to either the intermediate frequency filter or the bypass circuit.

Abstract: A radio frequency circuit includes a first differential RF path and a second differential path. The first differential RF path includes at least one RF block that includes a first differential section and a second differential section, wherein the first differential section is symmetrical with the second differential section. The second differential RF path includes at least one RF block that includes a first differential section and a second differential section, wherein the first differential section is symmetrical with the second differential section. The first and second half differential sections of the at least one RF block of the first differential RF path are symmetrically placed on at least one layer around the first and second half differential sections of the at least one RF block of the second differential RF path, wherein the first and second half differential sections of the at least one RF block of the second differential RF path are fabricated on the at least one layer.

Abstract: A receiver (202) has a down-conversion receiver (304) for transforming a signal (201) from a first operating frequency to a second operating frequency that is lower than the first operating frequency, and a receiver filter (308) with chopper stabilization for filtering unwanted portions of the signal (306) at the second operating frequency and for generating a final filtered signal (203) at the second operating frequency.

Abstract: A receiver with adjacent interfering wave elimination function that efficiently eliminates an interfering wave adjacent to a desired reception wave and has few distortion in the receiving signal after detection, is provided with a plurality of bandpass filters for detecting an adjacent interfering wave near a desired reception wave, detects adjacent interfering waves near the desired reception wave, and controls the bandwidths of the bandpass filters that pass the desired reception wave according to the occurrence of the adjacent interfering wave. According to another aspect of the present invention, the bandpass filter for detecting the adjacent interfering wave is made of a digital filter whose center frequency is variable, and the adjacent interfering wave is detected by scanning a frequency region adjacent to the desired reception wave with the digital filter.

Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.

Abstract: The present invention is a method and apparatus for optimizing performance of a transceiver selecting and processing an intermediate frequency free of significant interference, such as noise. A frequency band may be scanned to detect interference upon which an intermediate frequency free of significant interference may be selected. This may enhance performance of the receiver by reducing the effects of noise. Additionally, perrformance may be further optimized by adjusting the passband of the filter such that the center of the passband matches the selected intermediate frequency. This may provide stability as centering of the passband may account for process, voltage and temperature variations and errors. Further, performance may be enhanced by ensuring desirable signal attributes are passed through the filter.

Abstract: The radio signal receiving device that has an input terminal for inputting an input signal and an output terminal for amplifying the signal inputted to the input terminal and then outputting the signal, comprises an insulating container comprising the input terminal and the output terminal, and an amplifier that is contained in the insulating container and amplifies the signal and then outputs the signal as the output signal. Bias voltage from one of the amplifier input terminal of the amplifier and the amplifier output terminal of the amplifier is applied to the output signal outputted to the amplifier output terminal of the amplifier.

Abstract: A multiple-section bandpass filter for broadcast communications includes adjacent waveguide segments with a perpendicular connecting segment between them to form a U-shaped signal path. The waveguide cavities of the segments may be extruded and rectangular in cross section, and have a groundplane spacing that allows signal propagation between filter sections by evanescent coupling. Resonators in each of the adjacent segments have a separation that establishes the coupling bandwidths without the need for passive decoupling structures. A cross coupling conductor between the adjacent segments provides a capacitive or inductive coupling between them. A decoupling structure may be located in the connecting segment.

Abstract: A direct conversion circuit that not only down-converts the received modulated signal using a down-converting mixer into a baseband signal, but also, after performing a passive low pass filtering to remove higher-order components, performs up-conversion of the baseband signal using an up-converting mixer. Active elements such as highly sensitive amplifiers do not operate on the baseband signal itself, but on the up-converted version of that baseband signal, thereby reducing the 1/f noise introduced by those active elements. The downstream circuitry after the up-conversion may be coupled by intervening capacitors since the downstream circuitry is operating on a higher frequency signal. Accordingly, the DC offset introduced by the downstream active elements is reduced.

Abstract: A direct conversion satellite tuner is fully integrated on a common substrate. The integrated tuner receives an RF signal having a plurality of channels and down-converts a selected channel directly to baseband for further processing. The integrated tuner includes on-chip local oscillator generation, tunable baseband filters, and DC Offset cancellation. The integrated tuner can be implemented in a completely differential I/Q configuration for improved electrical performance. The entire direct conversion satellite tuner can be fabricated on a single semiconductor substrate using standard CMOS processing, with minimal off-chip components. The tuner configuration described herein is not limited to processing TV signals, and can be utilized to down-convert other RF signals to an IF frequency or baseband.

Abstract: A method for I/Q mismatch calibration in a receiver. The receiver has an I/Q correction module using parameters Ap and Bp. The method comprises the steps of generating an analog test signal x(t), applying I/Q demodulation to reduce the central frequency of the signal x(t) by fc Hz and outputting a demodulated signal xdem(t), converting the analog signal xdem(t) to a digital signal xdem[n], sending the signal xdem[n] into the I/Q correction module using parameters Ap and Bp and outputting a corrected signal w[n], obtaining two measures U1 and U2 of the corrected signal w[n], and updating the parameters Ap and Bp of the I/Q correction module respectively by a first and second function of the two measures U1 and U2, and the current values of the parameters Ap and Bp.

Abstract: A transceiver system is described herein that has an antenna coupled to a filter unit which is coupled to multiple radio base stations (RBSs). Each RBS uses one TX/RX cable and if needed a RX cable to connect to the filter unit. To enable the RBSs so they can share one antenna, each RBS has a duplex filter incorporated therein. And, the filter unit has a unique combination of diplex filter(s), duplex filter(s), part-band duplex filter(s), diplex-duplex filter(s), splitter(s) and/or low noise amplifier(s). Four exemplary embodiments of the transceiver system are described herein to show how the filter unit can be configured so as to enable the RBSs to share one antenna even if the RBSs share the same frequency band and/or even if the RBSs operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM). Also described herein in accordance with the present invention are: (1) a method for constructing the transceiver system; (2) a radio base station; and (3) an antenna.

Abstract: Channel selection of a received signal is first of all carried out, in the process, by way of an analog channel selection filter. The signal is then converted to a digital discrete-time and discrete-value signal. Finally, the continuous-time and continuous-value signal profile is determined on the basis of a mathematical reconstruction using the zero crossings {ti} and the phase values {?(ti)=ki·?/2, ki?N0}, with a mathematical reconstruction algorithm using a function system {?(t?k)}.

Abstract: First and second transmission paths P1 and P2 are disposed between a first port #1 connected to an antenna ANT and a second port #2 connected to a transceiving circuit 10. The first transmission path P1 includes receiving filters Rx1, Rx2, and Rx2?, an amplification circuit LNA, and 90° hybrid circuits 12 and 14. The second transmission path P2 includes a transmitting filter Tx1. A received signal amplified by the amplification circuit LNA is transmitted to the port #2 via the 90° hybrid circuits 12 and 14, but is not transmitted to the second transmission path P2. A transmission signal is transmitted from the port #2 to the second transmission path P2. This prevents oscillation of the received signal due to positive feedback.

Abstract: A subsampling receiver (50, 50?, 50?) for converting an RF signal to baseband is disclosed. The subsampling receiver (50, 50?, 50?) may be implemented into a wireless communications device (40), such as a wireless telephone handset. In one disclosed embodiment, the receiver (50) includes a sample and hold circuit (80) that samples a bandpass filtered input modulated signal at the subsampling frequency (fs) that is well below the RF carrier frequency but twice the bandwidth (BW) of the payload; the sampled signal is digitized, and applied to two digital mixers (85I, 85Q) to produce in-phase and quadrature components (I,Q) of the payload. In another embodiment, the receiver (50?) includes two sample and hold circuits (96I, 96Q) to sample the filtered signal at different phases of the sampling frequency, to produce the in-phase and quadrature digital components.

Abstract: A method and apparatus are described for providing an activation signal based on a received radio frequency (RTF) signal. The apparatus includes an RF receiver configured to admit a received RF signal in a given frequency band and a converter configured to convert the admitted RF signal to a proportional signal. The apparatus also includes a low power comparator that has a first and second input and an output. A biasing and offset compensation circuit is configured to bias the proportional signal higher by an offset midrange voltage and bias the second input to an offset compensated voltage based on an offset between the inputs of the comparator. The comparator is configured to receive the biased proportional signal at the first input and produce the activation signal at the output when a voltage difference between the biased proportional signal and the offset compensated voltage exceeds a comparison voltage threshold.