Abstract: A radar detector system and method. The system includes a front-facing antenna and receiver and a rear-facing antenna and receiver. The two receivers are electrically connected to a single control head that includes separate light and sound indicators for each of the front-facing and the rear-facing receivers. A tone generator is included in the module to identify audibly the front-facing receiver and the rear-facing receiver.

Abstract: A system for effecting radio communication over a given range of frequency channels among a plurality of participating local stations, includes: a variably settable channel transmission unit at each such participating local station; and a controller or central station having an interference array processor for receiving data characterizing the system and each such participating local station for assigning datum channels (frequencies) to each such participating station with prescribed channel spacing and what is termed a "book-page generator" for compiling data in successive book pages of initial and subsequent channel assignments for stations, with maintenance of such datum channel spacing. Further data compilations are made from the book-page generator in what are termed "station pages", comprising frequency shift instructions specific to the stations. Since a station page is derived from plural book pages, any station may be compromised without revelation of the contents of the book pages.

Abstract: When synchronous communication systems such as SONET (synchronous optical network) need to change data formats, the resulting periodically discontinuous clock signal associated with the data after overhead has been removed, has to be smoothed to a periodically continuous clock signal associated with resynchronized output data. The SONET format employs pointers which may be described as large phase hit error signals relative the clock signal. The present invention illustrates a technique for slowly integrating the large phase hit error signals into the clock smoothing process so that jitter in the smoothed clock output is held below previously obtainable limits. This is accomplished by high-pass filtering the large phase hit signal and summing it with the periodically discontinuous clock before applying it to a second order type 2 low-pass filter system which filter system employs phase locked loop synchronizing techniques.

Abstract: An arrangement is provided for selectively accessing and testing a digital telecommunications circuit (1) without detriment to the integrity of a signal carried thereby. The arrangement comprises an access unit (10) inserted in the circuit (1) to be tested, and test equipment (11) connected to the access unit (10) and through which the circuit to be tested can be selectively routed. The test equipment (11) includes a shift register (24) in its test circuit path. In order to match the delay introduced by the shift register (24) in the test circuit path, a similar clocked delay (21) is included in the access unit in the route followed by the telecommunications circuit (1) when undiverted. This delay matching avoids signal loss or repetition when switching the circuit to be tested between its undiverted and diverted paths.

Abstract: A method (100) is provided for a radio that is currently monitoring a first frequency f(1) to determine whether carrier activity exists on a second frequency f(2). The radio loads f(2) into the synthesizer (102). After waiting 17 ms (103), the radio makes a first determination (104) whether the synthesizer is locked on f(2). After waiting 17 ms (105), the radio makes a second determination (106) whether the synthesizer is locked on f(2). If the first determination and the second determination are both affirmative (107), the radio determines (120) whether carrier activity exists on f(2). Otherwise, after waiting 17 ms (108), the radio makes a third determination (109) whether the synthesizer is locked on f(2). If the second determination and the third determination are both affirmative (110), the radio determines (120) whether carrier activity exists on f(2).

Abstract: A microwave converter comprises circuit components formed on the outer surfaces of a three-dimensional body. The inner surfaces of the body constitute a grounding surface. A local oscillator is disposed on one of the inner surfaces. The three-dimensional body may be an electrically conductive body having a hollow space in which the local oscillator is disposed.

Abstract: In a battery-powdered system, a first integrated circuit provides a secondary power supply to a second integrated circuit, and also provides data signals in a serial protocol. The first integrated circuit steps down the secondary power supply when the reset-bar signal is being driven high. The second chip goes active whenever its reset-bar input exceeds its battery-voltage input.

Abstract: A customizable communications bus control gate array for facilitating communications between devices on two disparate digital communications channels. The gate array has a mask programmable integrated circuit with two I/O interface devices which are respectively connected to two different communications channels. The gate array also has a translating device connected to each of the I/O interface devices for translating electrical signals therebetween. Logic control is also provided and connected to both of the I/O interface device and to the translating device for controlling operations thereof so that predetermined communications requirements between both of the disparate communications channels are satisfied.

Abstract: A non-intrusive channel-impairment analyzer is provided for measuring at least one quasi-static impairment characteristic of a band-limited data communications channel. The analyzer comprises a data receiver section and a measurement section. The data receiver section is arranged to receive data modulated onto quadrature phases of a carrier signal in two quadrature forward processing paths. The receiver section includes a data recovery circuit for effecting a decision as to the identity of the original data on the basis of the outputs from said processing paths, and decision-directed compensation means disposed in said paths and arranged to compensate for channel-impairment effects on the received signal. The measurement section is responsive to signals generated in the receiver section during the receipt of random data, to derive a measurement of at least one said channel impairment, such as phase or amplitude jitter.

Abstract: A data communication system, including at least one base station and at least one portable module 120, wherein the portable module 120 transmits data on a high frequency, and the base station transmits data on a much lower frequency. Transmissions by the base station use a pulse-width modulation scheme where the most commonly used signals correspond to the shortest pulse. A "read" command is encoded as the same pulse width as one of the two write commands. Since the direction of data transmission is known in overhead, there will be no ambiguity.

Abstract: The programmable electronic device, such as a radio, includes a memory for storing program information. A controller, such as a microprocessor, is connected to the memory for programming and reading the memory. A keypad is provided for data entry and is connected to the microprocessor. A magnetic switch, such as a Hall effect switch, is located within the radio and controls the program enable line of the microprocessor. The Hall effect switch is actuated by an externally supplied magnetic field for enabling programming of the memory of the radio.

Abstract: In the radio communication system for performing a communication in the idle channel selected from a plurality of frequency channels, the originating call station transmits the station identification code to specify the distant station together with the idle channel data to be actually communicated, and the distant station designated by the station identification code shifts to the designated idle channel, and the communication is executed between two stations. During communication in a certain channel between two stations, in the case where a radio interference occurs in this channel and it is intended to shift to other channel, one station transmits the other channel data in the communication channel and the other station receives it, and the communication is continued each other in the other channel.

Abstract: In a millimeter wave monopulse first detector array for use in seeker applications in a guided missile employing quasi-optical, or Gaussian beam, signal transmission, a first detector is shown to include a patch antenna array, a mixer and a power divider in a monolithic implementation for extraction of the monopulse information in a radar receiver.

Abstract: A broad-band mixing circuit comprises a transmission line transformer connected between a port adapted to receive a radio frequency signal and a double balanced mixing section, the transformer serving to convert an unbalanced radio frequency signal into a balanced signal, a transmission line transformer connected between a local oscillation signal port and the mixing section, the transformer serving to convert an unbalanced local oscillation signal into a balanced signal, and a transmission line transformer connected between the mixing section and an intermediate frequency signal port, the transformer serving to convert the balanced signal from the mixing section into an unblaanced signal. The noise figure is improved by connecting an electrolytic capacitor in parallel with the balanced output end or the input end of the transmission line transformer for the local oscillation signal.

Abstract: A two-way radio includes a receiver having a squelch circuit and a selective calling decoder. A transmitter is connected to an inhibit circuit. The inhibit circuit is responsive to the selective calling decoder for permitting transmission after reception of the radio's ID code. The inhibit circuit inhibits further transmissions if the squelch circuit indicates loss of carrier for more than a predetermined time during receive.

Abstract: An antenna switch control circuit for use in achieving antenna selection diversity in TDM RF receivers. RSSI for at least one antenna is monitored during time slots containing information not of interest. This information can then be compared with other antenna performance information to allow a selection to be made such that the receiver generally operates with the antenna receiving the strongest signal. In one embodiment, all possible antennas are monitored during a time slot containing information not of interest. In another embodiment, RSSI for the selected antenna can be monitored during the time slot of interest, such that antenna selection can again be varied should the selected antenna diminish in performance.

Abstract: A mixer incorporating FET's (4,5) as the switching elements includes a resonant circuit connected as a tank circuit of the local oscillator (6) such that the inherence capacitance of the FET's is automatically compensated for. The harmonic recovery technique is also used by the inclusion of rejection filters at the input and output of the system, which rejection filters have reciprocal impedance characteristics, such as short circuit/open circuit or the like.

Abstract: In the radio communication system for performing a communication in the idle channel selected from a plurality of frequency channels, the originating call station transmits the station identification code to specify the distant station together with the idle channel data to be actually communicated, and the distant station designated by the station identification code shifts to the designated idle channel, and the communication is executed between two stations. During communication in a certain channel between two stations, in the case where a radio interference occurs in this channel and it is intended to shift to other channel, one station transmits the other channel data in the communication channel and the other station receives it, and the communication is continued each other in the other channel.

Abstract: A control system for an unattended transport car including a plurality of ground radio transmitters dispersed in a range within which the unattended transport car is movable, the transmitters transmitting positional information or the like by radio. The unattended transport car is provided with detecting means for detecting in a non-contact manner positional information concerning each of the ground radio transmitters memory means for storing a traveling course from a specific start point to a specific end point in the form of a series of pieces of positional information concerning the ground radio transmitters, and control means for effecting traveling course control and start-stop control every time the car passes one of the ground radio transmitters by constantly or intermittently comparing the positional information concerning each ground radio transmitter detected by the detecting means with the contents stored in the memory means.

Abstract: A method and system of radio data communications especially useful in communicating over a special communications channel between a base station or cell site of a cellular telephone system and one of many user stations. Each user station communicates an alarm condition which may be either a burglar type alarm or an environmental alarm to the base station by responding on a compelled basis to a status request from the user station. The responses to such request are prevented from overlapping by fixed and unique time delays for each user station. This status response requires substantially a single bit width of data. If no response is received, this is also sensed. Secondly, a different category of request acquires from each selected user station several bits of data constituting an informational message, the request being sent to each user station in a cell in sequence, along with the particular unique time delay for each user station.