Abstract: In a feed forward amplifier (100), a main amplifier (125) is coupled between an input (102) at which an input signal is received and an output (173) at which an output signal is provided. The output signal is an amplification of the input signal. A sample of the output signal is compared (144) with a sample of the input signal to produce a difference signal indicative of distortions introduced by the main amplifier (125). An error amplifier (165) provides a distortion signal which is an amplification of the difference signal, and the distortion signal is combined (169) with the output signal to compensate for main amplifier distortions. A random frequency, constant amplitude sine wave pilot signal is combined (117) with the input signal, and a correlation power detector (194,195,202,212,213) is provided to determine the magnitude of the pilot signal in the output signal. The gain and phase of the difference signal is then adjusted (155) to minimize the magnitude of the pilot signal in the output signal.

Abstract: Male and female radio frequency cable connectors 64 and 13 have corresponding circumferential grooves 80 and 44 which are aligned and face each other when the connectors 64 and 13 are in a connected state so as to form a channel. The connectors 64 and 13 are held together by a canted-coil spring 11 residing in the channel formed by the two aligned and facing circumferential grooves 80 and 44. Deformation of the canted-coil spring 11 residing in the channel allows the male and female counterpart RF cable connectors 64 and 13 to resist separation as well as provide a primary electrical contact between the two connectors. If a substantial tensile force is placed on the cables 12 and 85, the spring 11 will deform sufficiently to allow separation of the two connectors 64 and 13.

Abstract: A transistor mounting clamp assembly for ensuring reliable electrical connection of a power transistor electrical connector tab (typically the collector tab) to a metallized portion of an associated printed circuit board. The transistor mounting clamp assembly comprises a top and bottom clamp dimensioned for sandwiching therebetween the transistor tab. The clamp assembly uses a machine screw and associated Belleville washer for maintaining this urging relationship even when the components expand and contract. The bottom clamp preferably has a stepped region or other surface discontinuity for securing the connector tab thereto. The clamp assembly further comprises an extending tab which is secured to the top clamp and which has a second region for providing electrical connection to the metallized portion of the printed circuit board by soldering, or other means.

Abstract: A multi-cavity dielectric filter 30 having a single housing 32 for a plurality of resonant cavities 65. The dielectric filter 30 has a plurality of dielectric resonators 42 placed inside housing 32, instead of in individual housings, wherein the resonators 42 are spaced a quarter wave apart and are electrically isolated from one another by conductive isolation plates 44 positioned therebetween. The isolation plates 44 do not make continuous mechanical contact with the interior conducting surface of housing 32, but rather are spaced from the inner surface 77 of housing 32, thereby making assembly of the filter much simpler than if a solid RF connection had to be made. The resonators 42 are positioned inside the housing 32 between the isolation plates 44 and are supported by low loss, low dielectric constant spacers 46. End walls 59 complete the cavity formation at the termination ends 79 of housing 32.

Abstract: A TE.sub.101 mode cavity resonator housing 60 has a truss 70 securely mounted to one of its broadwalls 72. The truss 70 is fabricated from a material having a lesser coefficient of expansion than that of the material from which the housing 60 is fabricated. The difference between the coefficients of expansion results in a difference in expansion and contraction of the materials over temperature. The thermal expansions and contractions in the housing 60 material result in variations in the natural resonant frequency of the housing 60. These variations in natural resonant frequency are compensated by offsetting thermal expansions and contractions in the truss 70 material.

Abstract: A technique for directly coupling multiple high frequency resonant cavity filters includes a common port 62 that is directly coupled to a coupling rod 76 that is mounted within a first high frequency resonant cavity filter housing 64 of a housing assembly 60. The coupling rod 76 is directly coupled by a conductor 74 to an coupling rod 72 that is mounted within a second high frequency resonant cavity filter housing 66. The conductor 74 passes through an opening 78 in a common wall 80 between the first 64 and the second 66 high frequency resonant cavity filter housings. Thus, both filters 64, 66 are directly coupled to the common port 62.

Abstract: A broadband antenna array, formed of pairs of horizontally-spaced dipoles that are balun-fed, uses an air dielectric microstrip binary-feed network to optimize antenna bandwidth. Each dipole is fed by a three-wire balun which maintains the proper current distribution on the dipoles over the operating bandwidth. The binary-feed network feeds each dipole individually to further optimize the antenna's pattern bandwidth. The binary-feed network is formed using a conductive ground plane with spaced conductors to utilize an air dielectric, thereby minimizing antenna losses in the feed network. The feed network impedances are chosen to give a broadband impedance match to the dipoles, and the entire assembly of binary-feed network and dipoles is mounted in a reflector box, the dimensions of which are chosen to control the antenna beamwidth. Vertically stacked pairs are used to compress the vertical radiation pattern for greater antenna gain.

Abstract: A folded high frequency resonant cavity filter 30 includes a filter housing 32 that contains a half-wave resonator rod 36, 64 and a plurality of evanescent mode resonator rods 34, 34'. The half-wave resonator rod 36, 64 and plurality of evanescent mode resonator rods 34, 34' are mounted to the filter housing 32 such that they all lie along a single plane. The filter housing 32 has an inner wall 42 that physically isolates two groups of evanescent mode resonator rods 34, 34' from each other. An aperture 40 is is formed in the inner housing wall 42 between two physically opposing evanescent mode resonator rods 34' to allow a capacitive cross-coupling to occur between the two evanescent mode resonator rods 34'. The capacitive cross-coupling is fine tuned by a tuning rod 44 that is positioned through the inner wall 42 and within the aperture 40.

Abstract: A vehicular multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. The antenna is provided with a base section fixedly mounted on the vehicle and a removable antenna mast section removably received in the base section.

Abstract: A retractable motorized multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. In order to transfer the coaxial input signal to an output coaxial connector, a slip ring connector is provided. The slip ring connector is impedance matched to the antenna to create low VSWR at RF frequencies.

Abstract: In a circulator/isolator device used in a cellular transmission network, a centering ring is used to position the garnets with respect to the center conductor, magnets and pole piece. The clamping action of the housing holds the unit together. Because the ring centers all components, additional fixtures are not needed and inaccurate "eyeballing" by the assembler is eliminated. The garnets are held in place during assembly by the centering ring thereby eliminating the need for adhesive or dielectric grease.

Abstract: A removable antenna mounting device is adapted to receive an antenna such as that used for a mobile cellular telephone. The antenna is mounted to an antenna mounting member which operationally engages a trunk lid clamp member secured to the trunk lid of the vehicle. In order to provide positive engagement between the antenna mounting member and the trunk lid clamp member, an eccentric cam connection is provided. The eccentric cam connection is designed to facilitate the removal of the antenna from the trunk lid for storage in the trunk.

Abstract: A duplexing filter filters high frequency electromagnetic signals operating in two different frequency bands and uses a common coupling line mounted within an overall housing. Both filters use resonators and may be configured as combine or interdigital type filters. The high frequency filter has at least some of its resonators mounted on a base plate which in turn is positioned at a location along the length of the common coupling line so as to couple the higher frequency filter at its approximate quarter-wave location.

Abstract: A multi-band antenna is adapted to receive signals in the AM/FM bands and to receive and transmit signals in a significantly higher frequency band such as that used for cellular telephone. An AM/FM band antenna is formed of a tubular rod, and a higher frequency band antenna is formed using a centerfed coaxial dipole mounted on top of and coaxially with the AM/FM antenna. The dipole is fed by a coaxial rod attached to a coaxial cable extending through the AM/FM antenna. A cylindrical choke is disposed about the coaxial rod and is spaced a predetermined distance from the dipole antenna to reduce coupling between the AM/FM antenna and the high-frequency antenna. The choke functions to position the input impedance of the high-frequency antenna at the base of the choke in a manner so that a short matching transformer may be used at the base of the choke for connection to the coaxial cable.

Abstract: A bandpass/lowpass filter comprises a bandpass filter with two or more resonators with the first and last resonators coupled to associated connectors. Corresponding lowpass filters are positioned within the first and last resonators, wherein each lowpass filter comprises a plurality of low impedance and high impedance elements. A disk emanates from each of these integrated lowpass filters so as to couple the filtered electromagnetic energy to the bandpass filter. The overall result is an integrated filter having a desired bandpass with significant suppression of spurious frequencies. The overall integrated filter is significantly smaller than conventional filters using external inline lowpass filters.

Abstract: An n-way signal splitter having isolated outputs with a printed circuit board geometry providing the necessary crossovers with impedance lines, running under and orthogonal to resistive components, fabricated in microstrip on one side of the board, with a ground plane completely covering the other side, requiring no feedthrough holes or jumper cables to provide the necessary crossovers, and input and output connectors being fastened directly to the printed circuit board.

Abstract: An antenna base having a metal foot and plastic bezel injection molded around the metal foot to engage the metal foot. Double sided adhesive tape connects the antenna base to a non-conductive surface of a motor vehicle. In most instances this is a motor vehicle windshield. Inside the motor vehicle a coupling box connects communications signals from a signal source through the windshield to the metal foot. The coupling box supports a printed circuit board having conductive patterns on both sides for sending and receiving these communications signals. The metal foot also includes structure that allows an elongated antenna to be adjustably supported by the base in a signal sending and receiving orientation.