Abstract:
A power control loop for a power amplifier is disclosed. Embodiments of the power control loop include deriving a secondary control signal. The secondary control signal may be used to control a gain applied to the power signal in the power control loop and to control a supply current or voltage delivered to a power amplifier.
Abstract:
An adaptive band-pass filter for a wireless receiver comprises a band-pass filter associated with the receiver, the band-pass filter configured to selectively filter the received signal, and a switch responsive to a control signal, the switch configured to control the band-pass filter based on a level of the received signal.
Abstract:
A dual-band receiver for a wireless communication device having multi-slot capability. A first oscillator generates a relatively high frequency traffic LO signal. A second oscillator generates a first relatively low frequency signal, and a third oscillator generates a fixed low frequency signal. A first mixer mixes the first and fixed low frequency signals to produce a relatively high frequency monitor LO signal. A switch selects the traffic LO signal when the receiver is in a traffic slot and the monitor LO signal when the receiver is in a monitor slot. The selected LO signal is provided to a second mixer along with the received signal to produce a first IF signal. A third mixer mixes the first IF signal and the fixed frequency signal to produce an output signal.
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:
A voltage controlled oscillator operable on two widely separated frequency bands, such as 900 MHz and 1.8 GHz for example. The voltage controlled oscillator includes two negative resistance generators (32, 34) which share a common tunable tank circuit (26) and a common impedance matched combiner circuit (28) which provides the RF output (36). The VCO uses only one varactor (30) to tune both frequency bands. Separate negative resistance generators (32, 34) are used to provide optimum frequency selectivity within each frequency band.
Abstract:
Dual band voltage controlled oscillators (VCOs) incorporate a combiner circuit with a single output operable at two widely separated frequency bands such as 900 MHz and 1.8 GHz, for example. The combiner circuit includes a duplexer used as a combiner on the outputs of the VCOs. The duplexer can be realized in transmission line or inductor configurations. The use of the duplexer improves spurious performance and phase noise by more than 10 dB between the two operating frequency bands and supplies band rejection at the non-operating frequency.
Abstract:
A dual-band receiver for a wireless communication device having multi-slot capability. A first oscillator generates a relatively high frequency traffic LO signal. A second oscillator generates a first relatively low frequency signal, and a third oscillator generates a fixed low frequency signal. A first mixer mixes the first and fixed low frequency signals to produce a relatively high frequency monitor LO signal. A switch selects the traffic LO signal when the receiver is in a traffic slot and the monitor LO signal when the receiver is in a monitor slot. The selected LO signal is provided to a second mixer along with the received signal to produce a first IF signal. A third mixer mixes the first IF signal and the fixed frequency signal to produce an output signal.