Abstract: A meteor scatter communications system for communicating between a master station and one or more remote stations. In one exemplary embodiment, a broad beam transmitter probe signal is reflected from a meteor ionization trail to a remote station which then transmits a return data signal to the master station. The master station receiver has a plurality of antennas and a receiver beam forming network which forms a plurality of narrow beam receive signals, one of which has a high gain and corresponds to the narrow beam signal which illuminates the meteor trail and contains the reflected return data signal from the remote station. The master station processor selects such one narrow beam signal for processing the data therein.

Abstract: A single-block ceramic filter (102) is coupled to two antennas (142 and 144) for providing both antenna duplexing and antenna-summed diversity in a duplex radio transceiver (100). One antenna (142) is coupled by the filter (102) to a transmitter (132) and to a receiver (130), and a second antenna (144) is switchably coupled by the filter (102) to the receiver (130) by diversity control circuitry (101) in response to a diversity control signal (137). A microcomputer (134) in the transceiver (100) is coupled to the receiver (130) for monitoring the received signal strength (135). When the received signal strength (135) drops in level indicating that the signal being received on the antennas (142 to 144) has become degraded due to fading or other interference, the microcomputer (134) changes the binary state of the diversity control signal (137) for switching the receiver (130) between antenna (142) and both antennas (142 and 144).

Abstract: A combination battery pack and low profile antenna arrangement for use in conjunction with a two-way portable transceiver includes an enclosure containing an electrical battery with positive and negative electrodes. A pair of terminals are attached to the outer surface of the enclosure and are coupled to the positive and negative electrodes. A low profile antenna structure is disposed within the enclosure and includes a feed point for coupling RF energy to and from the antenna structure. An antenna coupling arrangement is electrically coupled to the feed point for coupling RF energy into and out of the enclosure.

Abstract: A watch type paging receiver which may be put on person's wrist by a belt includes a body on which a display device such as a liquid crystal display device is provided. An inverted F-shaped main antenna is implemented by a part of the display device. A loop antenna is provided in addition to the main antenna and implemented by the belt. The main and loop antennas are selectively rendered active depending upon the level of a received signal. Even when the length of the belt is changed to suit person's wrist, accurate matching is established on the basis of the resulting length of the belt. A primary battery in the form of a solar battery and a secondary battery are associated with the receiver body and the belt, respectively. A vibration source which is adapted for tactual alerting forms a part of the belt.

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: An interference cancellation system has a combiner which removes an undesired component from a main signal including both a desired signal and an undesired signal received by a main antenna. A power sensor measures output power of a main signal. A weight control circuit is coupled with an output of the power sensor. An auxiliary antenna receives an undesired signal. A variable complex weight control circuit adjusts an undesired signal from the auxiliary antenna according to the output of the weight control circuit to provide an input signal to the combiner. The variable complex weight control circuit operates so that the output power becomes a minimum.

Abstract: A burst-mode two-way radio communications system in which a plurality of antennas at a base station share a branched antenna switched dependent on the strength of the signal received from a portable transceiver, wherein a switch controller controls operation of one or more branch selection switches on the basis of an instructing signal received from any one of the base station transceivers.

Abstract: An interference cancellation system at a receiver side for digital radio system has a first quadrature phase detector for demodulating the main signal. A second quadrature phase detector (or a phase detector) is supplied with the same reference carrier and clock signal as that of the first quadrature phase detector, for phase detecting an interference signal. A decision circuit is coupled with the first quadrature phase detector to provide a baseband signal. An error signal detector provides a difference between a decision level of a digital signal and an input of the decision circuit due to the interference signal. A correlation device provides a correlation signal between an error signal and a phase detected interference signal. A control device provides a compensation signal which has the same amplitude and anti-phase as those of the interference component included in the main signal according to the correlation signal.