Abstract: There is provided a method of and apparatus for Automatic Frequency Control (AFC) of pure sine waves (PSW). It comprises discriminating to detect frequency differences between a received pure sine wave and a reference frequency, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference. It is further characterized by digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid to translate the pure sine wave to baseband, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and a reference frequency, integrating the frequency differences to average the differences, selectively calculating the mean variance between the pure sine wave and the reference frequency, and adjusting the reference frequency of a Voltage Controlled Oscillator to eliminate the frequency difference.

Abstract: An improved TDMA radiotelephone cellular communication system employs an improved cell site scan monitoring technique. The technique includes monitoring radiotelephone calls, and tracking and recording their signal qualities. The records are used to maintain and determine which frequencies and which time partitions at the base site equipment are being utilized for radiotelephone communication. When a new call assignment is required at a cell site, it is assigned to a time partition of a base site equipment frequency in a frequency prioritized manner such that radiotelephone calls are concentrated within each frequency so as to reduce the number of frequencies carrying radiotelephone calls.

Abstract: A system for rapidly detecting power disturbances with ferroresonant transformers having a decay profile comprising the steps of rectifying a power signal; comparing the rectified signal against a reference signal; comparing the rectified signal against a dynamic reference signal; and generating a power-fail signal in response to either comparison falling below its respective reference.

Abstract: A current-saving CMOS signal input buffer is provided, having at least two CMOS output transistors (each having an input) connected in complementary fashion with a common output taken therebetween, complementary current mirrors coupled to the output transistor inputs, an input signal capacitively coupled to at least one of the output transistor inputs, a reference impedance coupled between the complementary current mirrors, and isolation impedances coupled between the complementary current mirrors and the output transistor inputs.

Abstract: A register-modelled radio system comprising a plurality of register-modelled processors having addressable registers for modelling the virtual state of the processor; a serial bus, interconnecting the register-modelled processors for communicating between the addressable registers; and a communications protocol for passing information to or from the addressable registers, whereby the virtual state of a radio portion may be determined or altered by, respectively, communicating information from or to the addressable registers. The communications protocol further comprises an information packet having an address, an operation code, optional data, and an error detection device, such as a cyclical redundancy check packet. The operation code is chosen from the group of primitive operation codes reset, read, write, bit set, bit clear, acknowledge, and negative acknowledge.

Abstract: An improved fault detect algorithm and circuit is disclosed which quickly evaluates substantially all the elements within a successive approximation A/D convertor without resorting to off-line measurements. This method utilizes a small alternating offset signal injected into the correction loop in addition to the already converted value to determine whether the elements within this loop are operating properly for any in range analog input value.

Abstract: In accordance with the present invention, there is provided a register-modelled radio system comprising a plurality of register-modelled processors having addressable registers for modelling the virtual state of the processor; a serial bus, interconnecting the register-modelled processors for communicating between the addressable registers; and a communications protocol for passing information to or from the addressable registers, whereby the virtual state of a radio portion may be determined or altered by, respectively, communicating information from or to the addressable registers. The communications protocol further comprises an information packet having an address, an operation code, optional data, and an error detection device, such as a cyclical redundancy check packet. The operation code is chosed from the group of primitive operation codes reset, read, write, bit set, bit clear, acknowledge, and negative acknowledge.

Abstract: In accordance with the present invention there is provided a common antenna signal path selectively coupled to a plurality of signal energy paths, including transmitter and receiver paths. The transmitter and receiver paths are selectively coupled to the common antenna signal path by semiconductive devices capable of being variably biased from conductive to nonconductive states. In the transmit mode, the magnitude of the RF signal energy is detected and developed to adaptively maintain the disabled semiconductive device in a reverse biased or nonconducting state.

Abstract: Disclosed, herein, is an Automatic Gain Control (AGC) signal processor and a method for generating an AGC signal in a phase-locked receiver. An incoming signal, exhibiting both coherent and incoherent characteristics, is filtered to obtain the desired bandwidth. The filtered signals are amplified to maintain an amplitude relationship between the coherent and incoherent signals. The incoherent signals are conditioned in the same circuit, but in a different manner, than coherent signals are conditioned. The conditioned signals are utilized to generate an AGC signal such that an AGC signal is generated in a single circuit for both coherent and incoherent signals, although by differing circuit responses, depending upon the conditioning of the incoming signal.The preferred embodiment of the novel AGC processing contemplates a full wave rectifier as its signal conditioner. Another embodiment contemplates negative peak detection as its conditioner.

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: In accordance with the present invention, there is provided a Loran C cycle slip reduction technique that consists of sensing the signal to noise ratio and narrowing the phase locked loop bandwidth when a predetermined signal-to-noise threshold is exceeded.

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 general purpose data control terminal which permits multiple terminal control. The terminal is programmable thereby permitting compatability with a wide range of communications systems. The unit is microprocessor based and includes a keyboard, and display, and utilizes acknowledge and retransmission logic for improved reliability.

Abstract: A general purpose data control and information system particularly well adapted for multiple unit radio communications providing reliable enhancement to normal voice systems. The system provides addressing capability along with data transfer and utilizes handshake and retransmission protocol to enhance flexibility and reliability. The system utilizes fixed length signalling packets, with error correction encoding, to permit data transfer, transmitter identification and control and status monitoring.

Abstract: A data signalling system for transmitting signals between at least one primary station and a plurality of secondary stations. The system is well adapted for use in multiple unit radio communications systems capable of noise and data communications. A register model is utilized which permits a highly flexible signalling system compatable with a wide range of communications networks. Data transfer is accomplished using fixed length data packets which are error correction encoded and transmitted utilizing PSK modulation.

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.