Abstract: Embodiments of an active bandpass filter are described. Such a filter includes a transistor; a series-tuned inductive-capacitive (LC) network (STLCN) in a common source circuit associated with the transistor to produce a tuned degenerative filtering of at least one interfering signal; and a first, variable resistance associated with the STLCN to provide a first control of a resonance quality factor (Q) associated with the filter. Other embodiments may be described and claimed.

Abstract: A radio frequency tuner comprises one or more tracking filters ahead of at least one frequency changer. A controller has a filter alignment mode and a reception mode. Each filter has one or more resonant networks comprising an inductance and a switched capacitor network which is digitally controlled for selecting the network resonant frequency. In the alignment mode, the controller determines the difference between the nominal and actual capacitances of the network for achieving a known resonant frequency in order to determine a correction factor for the capacitor network. The correction factor is then used during normal reception by the tuner.

Abstract: A variable signal delaying circuit comprising an analog delay line having a control input for controlling the variable delay. A phase detector compares the input and output signals of the delaying circuit and supplies an output signal to a charge pump and integrator. A pulse stream generating arrangement produces pulse streams of different pulse widths and pulse control logic controls a selector for selecting any one of the pulse streams. In a first mode of operation, the control logic monitors the charge pump/filter output and selects the pulse stream which minimizes change in the output. The selection is fixed and the output of the charge pump/filter is then supplied as a correction signal to the control input of the analog delay line. Such an arrangement may be used to maintain minimum phase imbalance in I and Q signal paths of a quadrature frequency converter.

Abstract: In some embodiments, a radio transmitter assembly comprises a test signal generator module to generate a first instance of a test signal, the test signal comprising a code, a test signal receiver module which receives the code, a signal combiner to combine the first instance of the test signal with a real signal to create a combined signal, a radio signal generator to generate a radio signal from the combined signal, a signal separator to separate a second instance of the test signal from the radio signal, and comparator logic in the test signal receiver module to compare the code with a code embedded in the second instance of the test signal in the test signal receiver module.

Abstract: Embodiments of a zero intermediate frequency (ZIF) tuner are described generally herein. Other embodiments may be described and claimed.

Abstract: A pulse generator is provided for generating pulses with a selectable variable width and/or delay. The pulse generator comprises an oscillator and a selecting arrangement for selecting how many of a first group of delay elements are connected in series for delaying the oscillator signal. Identical delay elements are connected in series to form a second group. A measuring circuit repeatedly measures the delay provided by the second group, for example providing output pulses whose width or duration is equal to the delay. A reference pulse generator generates a series of reference pulses, each of which is a predetermined fraction of the oscillator period. A control circuit compares the measurement and reference pulses to generate an error signal that is fed back to timing delay control inputs of all the delay elements such that the widths of the measurement and reference pulses are made substantially equal to each other.

Abstract: Embodiments of an active bandpass filter are described generally herein. Other embodiments may be described and claimed.

Abstract: A universal highly integrated television tuner is provided for receiving television signals of many different types and standards from terrestrial or cable sources. The input signals are supplied to an RF attenuator forming part of an automatic gain control loop. A tracking low noise amplifier supplies the signals to a tracking filter. The filtered signals are supplied to a first frequency changer 105, 108, 110, which performs up-conversion to a high first intermediate frequency. The resulting signal is filtered before being supplied to a second frequency changer performing down-conversion to a conventional second intermediate frequency. The resulting signals are supplied to an automatic gain control detector and to second intermediate frequency filters. The detector detects the signal level upstream of the single channel filtering.