Abstract: An architecture for a multiple-band wireless transceiver with quadrature conversion receiver and transmitter circuits. A common, or shared, local oscillator is used to provide the necessary frequency up and down conversion signals for the transmitter and receiver circuitry, respectively. Each of the transmitter and receiver circuits include multiple, e.g., three, signal paths for providing multiple-band operation. In the transmitter, the outgoing baseband data is quadrature modulated. The modulated data signals are then frequency up converted using another quadrature signal mixing process which avoids any need for image signal rejection filters within the signal transmission path. Similarly, in the receiver, quadrature signal mixing is used for the frequency down conversion process, thereby avoiding any need for image signal rejection filters within the signal reception path. The down-converted data signals are then quadrature demodulated to produce the incoming baseband data.

Abstract: The invention relates to a tuner with at least a first and a second frequency band and with means for effecting a switch-over between the frequency bands, which tuner comprises a signal input terminal for the supply of a frequency information signal. The invention is characterized in that the tuner comprises a band selection circuit which is provided for the selection and control of one frequency band at a time, and in that the tuner comprises a frequency search function for tuning to a frequency, which function in a first step is designed to test the tuning possibility of the frequency in the first frequency band and, if tuning in the first frequency band is not possible, in a second step is designed for testing the tuning possibility of the frequency in the second frequency band.

Abstract: An electronic alignment system for a television signal tuner utilizes first and second controllers for generating respective first and second control signals for respective first and second signal processing circuits of a signal processing arrangement, with the first and second signal processing circuits having respective first and second tunable elements responsive to the respective first and second control signals. A deviation range of the first control signal is higher than a deviation range of the second control signal.

Abstract: The present invention provides a large capacity, user defined audio content delivery system. The system delivers uninterrupted music and delivers information content (e.g., news by evaluating and encoding an input audio stream while outputting another stream. Undesirable audio content (e.g., advertisements and unwanted news) are not present in the output audio stream as only desired portions of information content are stored for playback on demand. The invention also includes a user interface that is simple enough to facilitate utilization of the audio system in an automobile and employs standard hardware available in typical computing and/or personal digital assistant equipment. Additionally, the audio system can be portable (e.g., as portable as a personal digital assistant) and can be updated in real time or off line via a personal computer.

Abstract: A receiver (10) for a wireless telecommunications system that provides relatively wideband signal processing of received signals without increased signal distortion so that multiple received signals can be simultaneously processed. The receiver (10) includes a specialized LNA (16), frequency down-converter (18) and ADC (20) to perform the wideband signal processing while maintaining receiver performance. The frequency down-converter (18) employs a suitable mixer (28), BPA (32), attenuator (34), and transformer (36) that are tuned to provide the desired frequency down-conversion and amplitude control over the desired wideband. The down-converter devices are selected depending on the particular performance criteria of the ADC (20). A specialized digital channelizer (22) is included in the receiver (10) that receives the digital signal from the ADC (20), and separates the signals into the multiple channels.

Abstract: The present invention relates to a self-adaptive band-pass filtering device in a microwave signal transmitter and/or receiver, the receiver being connected to a microwave signal receiving antenna (1) connected to the input of a low-noise amplifier (2), a mixer (4) that receives, on the one hand, the output signal of the low-noise amplifier (2) and, on the other hand, the signal from a frequency synthesizer (5), characterized in that the self-adaptive filtering device (3) comprises, upstream of the amplifier (2), on the one hand, at least one filtering means (300, 31, 32) having at least two different frequency bands and, on the other hand, means (8, 33, 34) for selecting either a filtering means (31, 32) or one of the frequency bands depending on the frequency of the signal to be received.

Abstract: A near-unity divider apparatus in a direct conversion communication device includes a reference frequency, that is not on-channel, input to a multiply-by-two circuit that doubles the reference frequency. A divide-by-three circuit divides the doubled frequency by three to provide a first fractionally-divided frequency at a transmit or receive frequency. A delay generator inputs the first fractionally-divided frequency from the divide-by-three circuit and provides a second fractionally-divided frequency delayed a predetermined time period. A gate circuit combines the first and second fractionally-divided frequencies to provide a transmit or receive frequency with an adjustable duty cycle dependant upon the predetermined time period.

Abstract: A dual band telemetry system useful for monitoring patients in a care unit of a health care facility. The system includes an antenna system with a first antenna tuned to receive a signal in a first frequency band, a second antenna tuned to receive a signal in a second frequency band, a down converter for producing a frequency translation signal, and a mixer coupled to the second antenna. The mixer combines the signal received by the second antenna with the frequency translation signal to produce a signal having a frequency in the first frequency band. A combiner coupled to the mixer and the first antenna combines the signal generated by the mixer with the signal received by the first antenna. The combined signals are ultimately delivered to a central station for processing.

Abstract: Reduction in the time required for an Advanced Television Standards Committee (ATSC) digital television tuner to equalize, converge, and acquire a digital television signal suitable for viewing, wherein early model ATSC tuners also include a National Television Standards Committee (NTSC) analog tuner, is achieved by using a microprocessor to control use of the NTSC tuner to scan television channels. A channel measurement module converts the scanned analog signal to a digital signal, and the equalization coefficients for the resultant digital signal are stored in memory. The equalization coefficients stored in memory are then accessed and utilized to tune in new channels on the ATSC tuner. The amount of time necessary for the ATSC tuner to tune in a new channel is thus reduced. When the ATSC tuner is in use, the equalization coefficient data stored in memory are periodically updated.

Abstract: A tuning arrangement in a radio receiver includes a front-end circuit having a tunable band-pass filter that is capable of tunably selecting channels within at least one frequency band of an RF signal. A noise source coupled to an input of the tunable band-pass filter introduces a wide-band noise signal into the front-end circuit. A signal detector coupled to an output of the front-end circuit measures at least one signal power associated with a filtered noise signal derived from the wide-band noise signal. A tuning controller, coupled to the tunable band-pass filter by a tuning control signal, adjusts the tuning control signal in response to the at least one measured signal power for tuning the tunable band-pass filter to a desired filter response.

Abstract: The present invention provides an improved receiver capable of receiving either a satellite broadcast signal or a cable TV signal associated with a TV. The inventive receiver comprises a first BPF for filtering received broadcast signals, a first local oscillator for generating a first oscillation signal, a first mixer for generating a first IF signal, a SAW filter producing a waveformed band signal, a second local oscillator, for generating a second and a third oscillation signal, a second mixer for generating a second and a third IF signal, a switching block for switching the second and the third IF signal, a second BPF for producing a baseband channel signal selected from the cable TV signal, a first LPF for producing a baseband I signal of satellite broadcast channel, a shifter for shifting a phase of the third IF signal, a third mixer for generating a phase-shifted third oscillation signal, and a second LPF for producing a baseband Q signal of satellite broadcast channel.

Abstract: A dual-band transceiver operable in two different bands is disclosed. A local oscillator generates a fundamental frequency and a second harmonic frequency. A receiving circuit receives a high-frequency signal in a selected one of the two different bands using the fundamental frequency and a transmitting circuit transmits a high-frequency signal in a selected one of the two different bands using the second harmonic frequency. A transmitting operation in the first band is performed in a time period while a receiving operation in the second band is performed in the time period. A received signal obtained by the receiving operation in the second band in the time period can be used to measure a radio condition of the second band during communication in the first band.

Abstract: A filter system comprising three or more filters, each having different passbands, and an impedance adjusting network coupled between a filter system ports and each of the ports of at least two of the filters to adjust the port impedances of the filters coupled to the network. The adjusted port impedance of each filter at a frequency representative of at least one of the other filters coupled to the network is at a non-loading level. In one embodiment, the filter system is configured for use in a wireless communication receiver and/or handset.

Abstract: An antenna circuit which is improved the deterioration of amplitude characteristic in a strong electric field, an antenna circuit for AM broadcasting which can surely inhibit and damp FM-band signals in the strong electric field and amplifies to output AM-band signals, and an antenna circuit for AM/FM broadcasting in which AM-band signals are not damped by means of an FM-band filter. In the first antenna circuit, the output signal of an antenna (10) is supplied to the base of a transistor Tr2 forming a current amplification type amplifier having a high-input and low-output impedance and the emitter of the transistor Tr2 is grounded through a coil L6 and connected to an FM receiver (16) through a band-pass filter (38). In the second antenna circuit for receiving AM broadcasting, an input terminal is connected to an AM amplifier circuit (36) through coils (L7) and L8 in series and to the gate G of a field effect transistor FET.

Abstract: A broadband signal radio communication device which is capable of transmitting audio signals in a frequency band wider than a normal transmission band from 0 to 4 kHz in a radio system such as Bluetooth which employs a radio communication link through weak radiowaves. A plurality of channels are set between the same master and slave out of three channels maximally available on a synchronous connection oriented (SCO) communication link. The band of a transmitted audio signal is divided into a plurality of sub-bands each having a bandwidth of 4 kHz using a sub-band analysis approach, and the signals in the respective bands are assigned to associated SCO links for transmission. On the reception side, the signals in the respective bands, received through the plurality of SCO links, are synthesized by a sub-band synthesis approach to reproduce an audio signal having the original frequency band.

Abstract: A portable radio terminal apparatus for transmitting and receiving signals in different frequency ranges which has an apparatus for switching the radio terminal apparatus over into a respective frequency range, an antenna and a first antenna matching circuit arrangement for matching the radio terminal apparatus to a first frequency range. The antenna arrangement includes only one antenna whereby at least a second antenna matching circuit arrangement is provided which, given a switching over of the radio terminal apparatus from the first frequency range into a second frequency range, can be connected to the first antenna matching circuit arrangement.

Abstract: To provide a circuit arrangement for converting a preferably analog input signal from at least a receiver, particularly at least a UHF or VHF receiver, into a digital output signal, said circuit arrangement (100) comprising:

Abstract: Disclosed is an RF receiver for receiving an RF signal of a prescribed reception band and converting the received RF signal to an IF signal of a selected reception channel in a mobile telephone.

Abstract: A tuner, for example, for a television receiver, includes a UHF and a VHF section and a mixer oscillator stage. It is known that the VHF frequency band has to be split in at least two parts to handle the VHF signals. To that end, the mixer oscillator stage uses two separate VHF oscillators and a detector to switch tuned parts of the VHF section. In this way, the performance of the tuner is improved.

Abstract: A dual channel receiver (100) includes a front end bandpass filter (120) that has a front end bandwidth, a first mixer (130), a second mixer (135), and two essentially identical receiver back ends (190, 195). The front end bandpass filter splits a received signal into a first signal (121) and a second signal (122) of essentially equal signal strengths and provides out of band isolation between first and second signal outputs (123, 124). The first mixer is coupled to the first signal and to a high side injection signal (131), and generates a first mixer output signal (132). The second mixer is coupled to the second signal and to a low side injection signal (136), and generates a second mixer output signal (137). Each of the two essentially identical receiver back ends is coupled to one of the first and second mixer output signals.

Abstract: Between one end of a high-band tuning coil in a primary tuning circuit and one end of a high-band tuning coil in a secondary tuning circuit, a first switch diode and a second switch diode connected in series are provided. A second coupling coil is provided between the ground and the connection point of the first switch diode and the second switch diode. Both first switch diode and second switch diode are set to a continuity state or a non-continuity state to switch between a high-band state and a low-band state.

Abstract: To simplify the circuitry in a television signal receiver having a radio-frequency tuner (1) and at least two subsequent surface-acoustic wave filters (2, 3), in which the radio-frequency tuner (1) filters a radio frequency television signal applied to its input and converts it to an intermediate-frequency television signal which is coupled to the surface-acoustic wave filter (2, 3), the radio-frequency tuner (1) has at least two outputs (6, 7) which supply the IF television signal converted to the intermediate frequency. Each output (6, 7) is associated with a switch (8, 9) for switching the associated output (6, 7) to a fixed reference potencial. A first input (10; 12) of the two surface-acoustic wave filters (2, 3) is coupled to a first output (6) of the radio-frequency tuner (1), and a second input (11; 13) of the two surface-acoustic wave filters (2, 3) is coupled to a second output (7) of the radio-frequency tuner (1).

Abstract: An electronic system 8 is disclosed herein. The system includes circuitry 10 for processing a signal and a plurality of antennas 12a-12b. A plurality of switches 22a-22b are also included. Each of the switches 22a-22b is coupled between the processing circuitry 10 and a corresponding one of the antennas 12a-12b. Each of the switches 22a-22b includes first and second power MOSFETs where the source of the first MOSFET is coupled to the source of the second MOSFET. The system further includes circuitry 28 for selecting of one of the plurality of switches 22a-22b to be on.

Abstract: A first local signal required for a downconverter of a reception system and an upconverter of a transmission system in a first band is generated by a synthesizer for generating a variable high frequency local signal. A second local signal required for a downconverter of a reception system and an upconverter of a transmission system in a second band is generated by mixing a signal generated by an oscillator for generating a signal at a relatively low fixed frequency with the first local signal using a mixer and filtering the result using a high-pass filter.

Abstract: A multiband mobile unit communication apparatus is disclosed which comprises: an antenna for receiving L FRQ bands of M radio wave SIGs modulated by N modulating methods, M>L, M>N, N≧L; a frequency synthesizer for generating a LO SIG; an IF SIG generation CKT for generating M IF SIGs using the LO SIG, the FRQ synthesizer generating the LO SIG such that the M IF SIGs have the same intermediate FRQ; a SW CKT for selectively outputting N IF SIGs modulated by the N modulating methods respectively out of the M IF SIGs; N filters for filtering outputs of N IF SIGs from the SW CKT and outputting N filtered IF SIGs respectively; a SW responsive to a SW CONT signal for selectively outputting one of the N filtered IF SIGs; and a quadrature demodulator for quadrature-demodulating one of N filtered IF SIGs and outputting baseband SIG. Different frequency bands of received signals are converted into IF SIGs having the same intermediate frequency.