A radio frequency transponder/repeater is provided wherein an array of receiving antenna elements is coupled to an array of transmitting antenna elements to provide a directional antenna system and including additionally an internal radio frequency source which is also coupled to the array of transmitting antenna elements. With such arrangement, an internally generated signal provided by the radio frequency source may be transmitted using the transmitting array of the Van Atta System.

A vibrator unit for use in a timepiece comprises a vibrator mounted within a ceramic case. A glass lid is airtightly sealed to the ceramic case by means of a soldering washer soldered between opposing surface portions of the lid and case. The soldering washer consists essentially of 90Sn-10Au solder alloy which enables formation of the airtight seal at lower and/or shorter soldering temperatures than would be the case with conventional solder alloys thereby avoiding an increase in the equivalent...

In a synchronization judging circuit, a measuring portion measures a signal to interference power ratio of a received signal at each frame. An averaging portion calculates a moving average of a series of signal to interference power ratios for a predetermined number of frames to produce a mean value at each frame. A counter counts a number of consecutive frames each of which the mean value meets a predetermined threshold requirement. The counter further compares a counted value with a predetermi...

A system and method for automatically generating a return beam in the direction of a received beam. The inventive system (10) includes a phased array antenna (12) for receiving a radio frequency signal having a first wavefront from a first direction. In response to this signal, the invention (10) provides a second signal having a second wavefront. The second signal is a phase conjugate of the first signal and is transmitted in a reverse direction relative to the direction of the first signal. In...

A cellular system using a code division multiple access (CDMA) scheme includes N (N is a positive integer) pilot channels and M (M is a positive integer) data channels. The pilot channels are used transmitting reference signals whose transmission signals are known in advance. The data channels are used for transmitting information. Each of the M data channels is made to correspond to one or a plurality of said N pilot channels.

A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a re...

Crosslinkable saturated and unsaturated carbosilane polymers are prepared by polymerizing vinyl substituted 1-silacyclo-pent-3-ene or vinyl substituted 1-silacyclobutane monomers in the presence of an anionic ring opening catalyst.

The invention is concerned with the use of sulfonamide derivatives of the general formula ##STR1## wherein R Signifies lower-alkyl, phenyl, benzyl, naphthyl, pyridyl or thienyl, optionally substituted by one or more lower-alkyl, lower-alkoxy, lower-alkyl carbonyl-amino, halogen, cycloalkyl, nitro, amino, methylenedioxy, phenoxy or benzyloxy substituents, and the aromatic rings, can, in turn, be substituted by nitro, halogen or amino, R.sup.1 -R.sup.4 signify hydrogen, halogen, hydroxy, lower-alk...

Communications link using the ionized trail of a meteor entering the atmosphere at an altitude of approximately 100 kilometers as reflectors to relay radio frequency energy beyond the horizon using a retrodirective adaptive loop. The retrodirective adaptive loop includes a plurality of conjugate antenna elements, with each conjugate antenna element having a spatial servo-loop circuit. At least two stations having antennas with conjugate elements are required for generating a retrodirective oscil...

Provided is an antenna transceiver system for transmitting and receiving voice, digital data, radar and IR signals, and for processing received signals for use by an operator. The system includes an antenna array having a plurality of radiating elements, each element connected to a transmit/receive ("T/R") module. Each T/R module includes phase shifters, as well as a phase conjugation module for transmitting a return signal to a location along a beam path of an incoming signal. Transmission of t...