Abstract: A unique apparatus for coupling radio frequency (RF) signals from a wireless communication device (200) to an external device by way of an I/O port (116). In particular, a connector having three adjacent contact elements (238) couples signals to an external device wherein the first and third contact elements (239, 241) are electrically coupled to a ground plane (302) and wherein the second or middle contact element (240) is electrically coupled to a conductive RF signal path (344). The ground plane and the conductive path (334) are preferably on a printed circuit (pc) board which is preferably a three layer board with the conductive path (334) located between two ground planes (302, 352). The connector is substantially covered with a shield (230) coupled by legs (248) to the ground plane (302) at apertures (332). A mating connector (400) also includes a shield (430) which is commonly grounded.

Abstract: A method and apparatus enables a communication device (100) to operate in multiple bands, such as GSM 900 MHz, DCS 1800 MHz, and DCS 1900 MHz bands, by eliminating the need for a mixer for each band. In a dual band GSM/DCS 1800 radiotelephone, for example, the local oscillator (LO) injection frequencies for both GSM and DCS bands are provided to a mixer (234) through the use of combination filters (222, 246). Thus, the duplexing and matching requirements to the mixer input are simplified and the signal losses are minimized. The common output ports of the GSM RX/LO combination filter and DCS RX/LO combination filter are duplexed to the input of the mixer. Also, the input impedance matching of the mixer is designed to match the impedance for the received signals in each band, as well as provide an RF trap at the IF frequency. The match at the output of the mixer is designed to match the impedance of the IF filter and provides a low impedance to RF input frequencies.

Abstract: The improved gain control circuit is comprised of an amplifier, a semiconductor device attenuator at the amplifier input, and unique control circuitry for controlling the attenuation factor of the semiconductor device. The amplifier is designed for low phase shift to minimize the time delay of its transfer function. The control circuitry responds to both positive and negative a.c. signal transitions at the amplifier output to initiate attenuator gain reduction. As with the amplifier, the control circuitry is designed for minimum response time. The combination results in an extremely fast a.g.c. attack time.

Abstract: An audio derived AGC signal for controlling RF and/or IF amplifiers in the radio receiver wherein a first control signal is developed by a circuit having a relatively slow response time when the audio output signal is below a predetermined value and a second control signal is developed by a circuit having a relatively fast response time when the audio output signal is at or above the predetermined value. The control signals are developed across a storage capacitor and a circuit is connected thereto for quickly discharging the capacitor when no signal is being supplied from the audio circuit.