Abstract: A fast attack Automatic Gain Control (AGC) loop (100) having the capability to selectably shape one or more decaying current sources (242, 260) contained within an off-channel feedback loop and an on-channel feedback loop of the AGC loop by sequentially and selectively switching out weighted transistors (Tr0, Tr1, Tr2, . . . , Tr10) of a plurality of weighted current mirrors (313, 379, 453, 519) at predetermined intervals (t0, t1, t2, . . . , t10).

Abstract: A multimode fast attack automatic gain control (AGC) circuit (100) includes an analog feedback loop and a digital feedback loop. The analog feedback loop is switched into the amplifier stage (102) by a first switch (126) when dynamic control of the gain attenuation is desired. The digital feedback loop is switched into the amplifier stage when attenuation is to be adjusted periodically, such as between sequentially received time slots in a time division multiple access (TDMA) mode of communication.

Abstract: A fast attack Automatic Gain Control (AGC) loop (100) having a first feedback loop with selectable responses shapes and a second feedback loop with selectable responses shapes. Response shape selection is based, in part, upon fast pull-down, overshoot recovery, and normal mode loop operation.

Abstract: A method for acquiring rapid automatic gain control (AGC) response in a narrow band receiver teaches opening the AGC loop (100), setting the gain control signal (106) amplitude of the AGC amplifier stage (104) to a known value, altering the gain control signal (106) amplitude over time, and monitoring the narrow band receiver for an output signal (112). Upon output signal (112) detection, halting alteration of the gain control signal (106) amplitude, closing the AGC loop (100) and commencing normal operation. A particular facet of this approach suggests detecting the output (112) with a varying gain detector (116,132) after the loop (100) is closed and before normal operations are commenced.

Abstract: A transmission line structure (100) is provided which includes a resonator (110) having open ends (118) disposed on a substrate (130). The first resonator (110) includes a control voltage terminal (116) which is positioned at a point along the length where a zero potential exists at resonant frequency. Transmission zero frequency is tuned by means of a varactor (150) which is coupled to the control voltage terminal and receives a control voltage for controlling the zero frequency.

Abstract: A transmission line filter is provided which includes a first resonator having open ends being coupled to a second resonator disposed on a substrate. A transmission zero frequency is tuned by means of a varactor which is coupled between the first and the second resonator. The first resonator includes a terminal for applying a control voltage to the varactor for varying its capacitance.