Abstract: A holster (100) formed a body wearable housing (102), a cable (120), and a holster antenna (104) provide retention for a portable communication device (202) along with remote antenna coverage to another portable communication device (302) via the holster antenna (104).

Abstract: A communication device (105,200) includes a cordless telephone (205) and a two way radio (210). The communication device (105,200) is adapted to place an active cordless telephone call in a low frequency mode in response to receiving an incoming two way radio communication. The communication device (105,200) is adapted to then establish communication within the two way radio communication. The communication device (105,200) periodically re-establishes the cordless telephone call to maintain communication with a cordless base station (120) until the two way radio communication is completed.

Abstract: A technique for activating a transmit mode of a communication device (100) is provided encompassing the steps of generating a light signal on an outer surface of the communication device; inhibiting the light signal; and activating the transmit mode of the communication device in response to the light signal being inhibited. A communication device (100) operating in accordance with this technique includes a light transmitting device (108); and a sensor (110) for sensing light generated by the light transmitting device, the sensor disabling a transmit mode when light is detected and enabling a transmit mode when light is inhibited.

Abstract: A communication device (105) includes a first communication block (205) for operation within a first communication network (150); and a second communication block (210) for operation within a second communication network (160). The communication device (105) further includes an audio control (245) for at least one microphone (250). The audio control (245) is coupled to the first communication block (205) for receiving a first audio input for operation of the first communication block (205) and is coupled to the second communication block (210) for receiving a second audio input for operation of the second communication block (210). A low noise ground (315) is isolated from a common ground (320) of the communication device (105) to facilitate the sharing of the at least one microphone (250) between the two communication blocks.

Abstract: A communication device (105,200) includes a cordless telephone (205) and a two way radio (210). The communication device (105,200) is adapted to place an active cordless telephone call in a low frequency mode in response to receiving an incoming two way radio communication. The communication device (105,200) is adapted to then establish communication within the two way radio communication. The communication device (105,200) periodically re-establishes the cordless telephone call to maintain communication with a cordless base station (120) until the two way radio communication is completed.

Abstract: A receiver (10) includes an antenna (12), a preselector (14), an amplifier (16), a mixer (18), a filter (20), a signal strength measurement circuit (22), a radio frequency signal detector (26), and a processor (24). The processor (24) is programmed to receive a signal indicator level (42) from the signal strength measurement circuit (22), generate an automatic gain control command (44) based on the received signal indicator level (42), and send the automatic gain control command (44) to the amplifier (16) to control a gain of the amplifier (16). The processor (24) is programmed to receive an off channel signal strength (48) from the radio frequency signal detector (26), compare the off channel signal strength (48) to one or more threshold levels, generate a filter command (46), and send the filter command (46) to the filter (20). The filter command (46) identifies a cutoff frequency for the filter (20).

Abstract: A receiver (10) includes an antenna (12), a preselector (14), an amplifier (16), a mixer (18), a filter (20), a signal strength measurement circuit (22), a radio frequency signal detector (26), and a processor (24). The processor (24) is programmed to receive a signal indicator level (42) from the signal strength measurement circuit (22), generate an automatic gain control command (44) based on the received signal indicator level (42), and send the automatic gain control command (44) to the amplifier (16) to control a gain of the amplifier (16). The processor (24) is programmed to receive an off channel signal strength (48) from the radio frequency signal detector (26), compare the off channel signal strength (48) to one or more threshold levels, generate a filter command (46), and send the filter command (46) to the filter (20). The filter command (46) identifies a cutoff frequency for the filter (20).

Abstract: A substrate 15 has an electrically adjustable trim pad 50 on the bottom side. A circuit pattern 18 resides on the top side, covered by an RF shield 20. The trim pad is located on the bottom side directly below the RF shield, and is electrically connected 52 to the circuit pattern. A number of surface mount connections 30, typically C5 solder bumps, are located on the bottom side, and surround the trim pad. The trim pad is trimmed after the RF shield is attached, thus providing more accurate tuning of the circuit on the top side.

Abstract: A phase noise optimization circuit (208) minimizes phase noise for a voltage controlled oscillator (VCO) (202). Control circuitry (214) locates a minimum phase noise region for VCO operation based on the slope of the VCO's changing control voltage (206) versus changing bias voltage (204) for a bias voltage range. The control circuitry (214) then adjusts the bias input so that the VCO operates in a region of minimum phase noise.

Abstract: A radio receiver operates primarily in a first operating mode to process received signals (410). When a carrier signal detect is triggered while in the first operating mode (415, 420), the receiver temporarily operates in a second operating mode which has receiver parameters selected to reduce carrier detect falsing when compared to the first operating mode (430). Preferably, in the second operating mode, the receiver's frequency and time response characteristics are modified to facilitate carrier squelch detection. Carrier squelch is performed if a carrier signal detect is triggered while the receiver operates in the second operating mode (440, 450, 460, 470).

Abstract: A self-tuning VCO (116) receives a control voltage input (Vcont) (114) and an adjustable programmable voltage (Vadj) (122) and provides optimized locked conditions even under variations in temperature. A radio temperature is measured and stored (204) while Vadj (122) is initialized and stepped and Vcont (114) attempts to lock the VCO on frequency. Once a locked condition is achieved, the Vcont (114) is monitored to determine if it falls within a predetermined voltage range. If a non-optimized condition is detected, then the Vadj (122) is automatically adjusted until the VCO (116) becomes locked with a Vcont which falls within the predetermined voltage range. When a locked condition is achieved, the radio temperature is monitored and compared (212) to the original stored temperature (204). If a temperature threshold limit is reached (216) then the VCO is re-checks itself for a locked condition and re-optimizes itself to accommodate for the variations in temperature.

Abstract: An oscillator circuit (100) provides improved noise immunity by utilizing a differential common base configuration. The oscillator includes a differential transistor pair (102, 104) having common bases (110) coupled through an AC ground (108) and emitters coupled through a differential common mode point (120). First and second resonant tank circuits are each referenced to the differential common mode point (120) for generating a differential output (OUT, OUTX).

Abstract: A high Q integrated inductor-capacitor (L-C) resonator (200) includes a planar inductor (201) having a plurality of turns and a serially connected first and second capacitor (205, 207) that is connected in parallel with the planar inductor (201). The first and second capacitors (205, 207) are positioned within at least one turn of the planar inductor (201) for reducing the parasitic interconnection resistance between the planar inductor (201) and first and second capacitor (205, 207) and also increasing the Q factor of the L-C resonator.

Abstract: A voltage controlled oscillator module (100) (400) provides tuning capability for the VCO in a shielded environment. The module includes a trimmable capacitor (110) (410) having metal plates (112, 114), (412, 414, 416) capacitively coupled through the substrate. One of the metal plates (114) (416) is a trimmable plate which can be trimmed to tune the VCO frequency. The trimmable metal plate (114) (416) remains exposed on the bottom surface (108) (408) of the substrate (104) (404) so that the frequency of the VCO can be tuned while the reminder of the oscillator circuitry (102) (402) on the top surface (106) (406) is encapsulated by a ground shield (116) (418).

Abstract: A voltage controlled oscillator module assembly (300) minimizes microphonics in a low profile package. Included within the module (300) are a substrate (302), VCO circuitry (308), and a ground shield (314) encapsulating the VCO circuitry. Included within the VCO circuitry (308) is at least one resonator (310) which is solderable on at least two of its surfaces. One surface of the resonator (310) is soldered to the substrate (302) while another surface of the resonator is soldered to the shield (314). An improved ground is thus provided to the resonator (310) which reduces the occurrences of microphonics while providing a low profile package for the module (300).

Abstract: An oscillator (100) includes a tank circuit (102) coupled to a an active circuit (108). The feedback (104) provides the necessary feedback between the tank and the active circuit necessary for oscillation. The active circuit (108) is biased via a biasing circuit (106) and coupled out to a load via an external coupling (110). The active circuit (108) includes two transistors (124, 126) coupled to each other in a cascode configuration. Transistor (126) provides the collector current for transistor (124) while preventing it from entering saturation prematurely. The biasing circuit (106) provides sufficient current drain for the transistor (126) in order to provide for optimum phase noise and bandwidth performance of the oscillator 100.

Abstract: An oscillator (200) with improved sideband noise is disclosed. This improvement is accomplished without affecting the Q or the output power of the oscillator (200). The improvement is realized by increasing the rate of change of reactance over frequency. The increase in the rate of change is realized by placing two transmission lines (208, 210) in close proximity of each other. This increase assures oscillation while minimizing the sideband noise, and providing maximum bandwidth.

Abstract: A bandpass filter, having an input port and an output port, comprises a first microstrip split-ring resonator coupled to input port, and a second microstrip split-ring resonator coupled to the first microstrip split-ring resonator, and coupled to the output port. A lumped or distributed capacitance is disposed between the first microstrip split-ring resonator and the second microstrip split-ring resonator.

Abstract: An integrated tunable resonator (100) includes a common semiconductor carrier (110). Formed on the common semiconductor carrier (110) is an integrated voltage variable capacitor (104). A bulk acoustic wave resonator is formed on the common semiconductor carrier (110) and coupled to the voltage variable capacitor (104). In one aspect of the present invention, a thin film resonator (106) is coupled to the voltage variable capacitor (104) both of which are formed on a common semiconductor substrate (110). The combination of these three elements provide for a tunable integrated resonator (100). In another aspect of the present invention, a surface acoustic wave resonator (522), formed on a common semiconductor carrier (514), is coupled to a voltage variable capacitor (520) in order to provide a tunable resonator (500).

Abstract: An integrated switch (100) includes a first input port (102), a second input port (112) and an output port (106). The integrated switch (100) comprises a first electronically-tunable integrated capacitor (104) having a control line (108) for selectively coupling the first input port (102) to the output port (106). The switch (100) also includes a second electronically-tunable integrated capacitor (110) having a control line (108) for selectively coupling the second input port (112) to the output port (106).