Abstract: An antenna array (200) having a number of patch antennas (202, 204, 206, 208) forming a circumferential radius is provided. The antenna array (200) is integrated within a body worn device (500) such as a belt, coat, or harness (210). Location tracking technology is used in conjunction with the antenna array (200) to select the optimal antenna from the array.

Abstract: An antenna array (200) having a number of patch antennas (202, 204, 206, 208) forming a circumferential radius is provided. The antenna array (200) is integrated within a body worn device (200) such as a belt, coat, or harness (210). Location tracking technology is used in conjunction with the antenna array (200) to select the optimal antenna from the array.

Abstract: A mounting apparatus (100) suitable for retaining an antenna (112) includes a base (102) having magnetic sources (104) and (106) capable of providing varying magnetic forces. Magnet (104) retains the base against a metal surface (410), while an electronically controlled magnet (106) provides additional retention of the base (102) against the metal surface (410) when activated, thereby preventing movement of the base and antenna (112).

Abstract: An electrical connector interface (10) provides for voltage surge protection. The connector interface (10) includes electrical interface conductors (12), an electrical ground conductor (14), and a selectively conductive material (18). The ground conductor (14) is spaced apart from the electrical interface conductors (12), and the selectively conductive material (18) is electrically coupled to the electrical interface conductors (12) and to the electrical ground conductor (14). The selectively conductive material (18) has low electrical conductivity within a predetermined voltage range, and has high electrical conductivity outside the predetermined voltage range.

Abstract: A method and apparatus for rapidly determining the resonance of a loop antenna (7). In order to set the loop antenna (7) to the desired operating frequency, the antenna is used with an amplifier (15). In view of the high Q provided by the loop, it is used at the output of the amplifier (15) to create a tank circuit. The loop is adjusted to create the proper amount of phase shift driving the amplifier (15) into oscillation. The antenna is then tuned to allow the amplifier (15) to oscillate at a desired frequency. This frequency is monitored on a frequency counter. When the desired frequency is attained, the loop antenna is properly adjusted and can be connected to a transmitter. The invention allows quick and easy adjustment of the loop antenna without having to apply RF energy to the antenna or make VSWR calculations.

Abstract: A retractable antenna assembly with a bottom connector (200) allows communication devices that require the use of more than one type of antenna element (114), to easily store the normally used antenna element (114) inside of a transmission line housing (144) which is part of the antenna assembly (200). Once inside of the housing (144), the antenna element (114) is hidden within the transmission line housing that has a 50 ohm impedance at the operating frequency of the communication device (302), thereby operatively decoupling the antenna element (114) from the radio frequency path. Once inside of the housing (144), the antenna element (114) is connected to part of a coaxial connector (112) with the bottom portion (120) of the antenna element (114) connected to the center conductor of the coaxial connector (112), thereby allowing for an external antenna element (308) to be attached to the communication device (302).

Abstract: A retractable antenna assembly with connector (200) allows communication devices that require the use of more than one type of antenna element (114), to easily store the normally used antenna element (114) inside of a housing (134) which is part of the antenna assembly (200). Once inside the housing (134), the antenna element (114) forms a half wave cavity that has a high impedance at the operating frequency of the communication device (302), thereby operatively decoupling the antenna element (114) from the radio frequency path. Once inside of housing (134), antenna element (114) forms part of a coaxial connector (112) with the top portion (116) of antenna element (114) forming the center conductor of the coaxial connector (112). Thereby allowing for an external antenna element (308) to be attached to the communication device (302).

Abstract: Switching system for use with a radio transmitter or the like to adapt the same for operation at two different power levels, including a flexible circuit connected to stages of the transmitter and to a switch to control the power level of the signal transmitted. The flexible circuit is very thin so that it can be positioned within the radio housing on the circuit board, and connected to terminals on the board and on the switch. The flexible circuit includes transmission line sections for making matched impedance connections to the transmitter stages for low power loss. The flexible circuit adjusts to take care of tolerances in the position of the terminals to which it is connected.

Abstract: First and second spaced apart, coextensive ground planes with a center conductor positioned therebetween in spaced relation from each of said planes and the volume defined by said planes being filled with a dielectric material fixedly engaging said planes and said center conductor to form a strip-line transmission line, the characteristic impedance of said transmission line being adjusted to a predetermined amount by forming a channel through one of said ground planes to the center conductor. The channel in the strip-line increases the characteristic impedance so that the width of the center conductor can be increased, for a specific characteristic impedance, to significantly improve control of the production of the strip-line.