Abstract: A communication system includes a vehicle (101) and an infrastructure (160). The vehicle contains vehicle system information (104) and user information (112). The infrastructure includes a processor (154) with an applications program (155). The application is arranged to remotely access (200, 300, 400 and 500) the vehicle system information in a secure manner. The application is also arranged to remotely access (600) the user information in a secure manner.

Abstract: A communication system (100) includes an infrastructure (150) and at least one vehicle (101), the vehicle including at least one vehicle system (103), and at least one user system (113). The infrastructure includes an application (155) which, in turn, is arranged to reprogram the vehicle system, the user system, or both.

Abstract: A vehicle (100) has a plurality of vehicle systems (11, 12, 13) and a plurality of user devices (40, 50, 60), each vehicle system including a unique function. The vehicle also has a vehicle bus (10) and a user bus (30), the vehicle bus coupled to the plurality of vehicle systems, the user bus coupled to the plurality of user devices, the vehicle bus coupled to the user bus by means of a gateway (20). Each function corresponding to each vehicle system is registered in the gateway. As a result, the user devices can determine and interact with the functionality of the individual vehicular devices.

Abstract: A mobile telephone system has a base transceiver station (BTS) that provides radio communication with a mobile handset (MS) and also communicates with a control station (BSC) through a communication link in the form of a leased line which provides a first communication path with a predetermined bandwidth for signals communicated between the BTS and the BSC. A communication network in the form of an ISDN is used to provide a selectively connectable second communication path between the BTS and the BSC so as to augment the bandwidth available for the signals during periods of peak demand. In order to accommodate different call connection times in the system through the leased line and the ISDN, the BSC/BTS are arranged to produce all connection signals that initiate billing at the same time irrespective of the path used to make the call connection.

Abstract: An antenna structure (108) operates in the presence of narrow or wide band interference and yet is able to enjoy high receiver sensitivity. This is done by steering the antenna structure (108) radiation pattern null in its near field at the noise source.

Abstract: EMI spur interference is reduced in a system where the desired signal has periodically repeating components without destructively interfering with the repeating components. The frequency of the spur interference is determined (203) and fed to a notch filter (201) so as to center the notch at the frequency of the spur interference. Determination of the frequency is scheduled (601) to avoid cancellation of desired periodically repeating components of the signal.

Abstract: Received signal strength calculations in a radio are carried out by hardware which scales the absolute value of components of the received signal in a linear fashion by using two scaling factors.

Abstract: A transmitter has an oscillator (101, 201, 303, 401, 501) that operates at frequency k multiplied by f.sub.c, thus the oscillator (101, 201, 303, 401, 501) outputs a signal at an output frequency, kf.sub.c. Coupled to the oscillator (101, 201, 303, 401, 501) is a frequency modifier (103, 205, 307, 405, 505), for modifying the oscillator output frequency by factor 1/k, thereby producing a signal at frequency f.sub.c at the frequency modifier output. Coupled to the frequency modifier output is a modulator (105, 215, 301, 407-417, 507-517) for producing a modulated output signal substantially centered at frequency f.sub.c.

Abstract: A data message (201) is transmitted (301) to a plurality of communication units (103, 105, 107, and 109). The data message (201) is received (401) by the plurality of communication units, which determine (403) whether the quality of the received data message is acceptable. When at least one of the plurality of communication units determines that the received data message is of unacceptable quality, the at least one of the plurality of communication units transmits (411) an energy burst (203) in a predetermined time window. Upon detection of the energy burst (203), the transmitting device may retransmit (309) the data message to the plurality of communication units.

Abstract: A noise source (113 or 217) is coupled to an analog-to-digital converter (115 or 219) so as to remove at least some unwanted spectral components from the analog-to-digital converter (115 or 219) output. In one embodiment, the noise source (113 or 217) is comprised of a sigma-delta digital-to-analog modulator.

Abstract: An analog signal having an input level is provided. The analog signal is converted into a digitized representation of the analog signal in an analog to digital converter (105) that uses an operating range. The digitized representation of the analog signal is processed (107) to determine the input level for the analog signal. The input level for the analog signal is compared (109) with a reference signal to provide a comparison signal. The comparison signal is manipulated (111) to adjust the operating range.

Abstract: An analog-to-digital (A/D) circuit comprising a multi-pole gain stage, a quantizer, and a feedback stage is stabilized when an analog input signal is excessive in the following manner. A stabilization detector continually samples a representation of stabilization of the A/D circuit. When the representation of stabilization is unfavorable, the stabilization detector increases, via a stabilizer, phase margin by adjusting the pole locations of the multi-pole gain stage based on the degree of unfavorability of the representation of stabilization. With the increased phase margin, the A/D circuit continues to provide digital representations of the analog input signal.

Abstract: An RF filter (100) includes a ceramic resonator (116) sandwiched between first and second compensating discs (114 and 120) for temperature compensation, low loss mounting and heat sinking of the ceramic resonator (116). Good thermal contact between the ceramic resonator (116) and discs (114 and 120) is produced by a compressive force applied by copper plates (112 and 128) and copper can (124). The resonant frequency of the RF filter is tuned by means of a copper-plated tuning shaft (104) and ceramic tuning slug (118) which are positioned by brass bushing (134) in copper pipe (130 and 132). Input and output signals are coupled to the RF filter via respective probes (122).

Abstract: A improved microwave dielectric oscillator module which is provided with a removable temperature compensated dielectric resonator channel element is described. The removable temperature compensated dielectric resonator channel element cooperates with an electrically shielded housing. A substrate is mounted within the housing. Microstrip or stripline conductive patterns deposited on the substrate couple energy from the removable dielectric resonator to the remainder of the oscillator circuitry. The oscillator achieves wideband operation utilizing a GaAs FET transistor as the oscillators active element in conjunction with an intergral trombone-line phase adjuster.

Abstract: In accordance with the present invention there is provided a bandpass T filter and power splitter for electromagnetic energy. It is composed of a plurality of resonant elements serially arranged to form a plurality of forward multi-pole bandpass filters. At least one resonant element is common to both signal paths. The common resonant element transfers energy from the common path to the independent signal paths to effect a power split. The two signal output paths are isolated from one another by a multi-pole bandpass filter. The resonant elements may be composed of either resonant waveguide cavities or dielectric resonators.

Abstract: There is provided a method and a corresponding apparatus for establishing the proper bandwidth at one frequency in a microwave, dielectric resonator waveguide filter.Bandwidth is determined by the product of the resonant center frequency and the interresonator coupling coefficient. The interresonator coupling coefficient has been found to vary depending upon the interresonator spacing as well as the position at which the resonators intercept the electromagnetic field distributed across the waveguide.This method establishes the proper combination of field-intercepting position and interresonator spacing such that the proper bandwidth is established at one frequency.

Abstract: A method and corresponding apparatus for maintaining constant bandwidth over a frequency spectrum in a microwave, dielectric resonator waveguide filter. Bandwidth is determined by the product of the resonant center frequency and the interresonator coupling coefficient. To maintain constant bandwidth while changing center frequency, the interresonator coupling coefficient must be chosen such that it varies inversely with changes in center frequency. The interresonator coupling coefficient is a function of the physical dimensions of the waveguide and the dielectric resonators, the dielectric constant and the spatial location of the resonators within the waveguide. Once the physical and spatial parameters have been established, the center frequency of the filter may be adjusted by altering the thickness of the resonators without changing the filter bandwidth.

Abstract: A method and corresponding apparatus for maintaining constant bandwidth over a frequency spectrum in a microwave, dielectric resonator waveguide filter. Bandwidth is determined by the product of the resonant center frequency and the interresonator coupling coefficient. To maintain constant bandwidth while changing center frequency, the interresonator coupling coefficient must be chosen such that it varies inversely with changes in center frequency. The interresonator coupling coefficient is a function of the physical dimensions of the waveguide and the dielectric resonators, the dielectric constant and the spatial location of the resonators within the waveguide. Once the physical and spatial parameters have been established, the center frequency of the filter may be adjusted by altering the thickness of the resonators without changing the filter bandwidth.