Abstract: A simulcast broadcast system wherein two signals (103 and 106) intended for simultaneous broadcast are transmitted from a source site (100) to remote sites (200) discrete from one another. At the remote sites, the two signals are separately processed, including the introduction of appropriate delay (305 and 312), prior to combining them for broadcast in conjunction with other remote sites. One or more monitoring sites (400) can also be provided to monitor reception coherence within the system and to provide operating measurement information to allow automatic control of various simulcast system parameters, including delay.

Abstract: A high-frequency dielectric ceramic compound having a perovskite-type crystal structure comprising a chemical composition substantially represented by the formula (Sr.sub.x Ca.sub.y Mn.sub.z)TiO.sub.3 in which 0.98<x+y+z<1.02,0.34<y<0.4, and 0.0075<z<0.015, and possessing a non-linear temperature coefficient is set forth. A method is presented for utilizing the compound to formulate a high-frequency dielectric material, the formulated material being particularly suitable for providing filters and related applications with a relatively low resonant frequency temperature coefficient.

Abstract: A single substantially non-programmable fully integrated circuit for a digital frequency modulated discriminator is provided whereby frequency variations of a digitized frequency modulated information signal are linearly converted to amplitude variations. Matched pairs of data words from the digitized information signal are used to obtain a phase octant, one of eight equal sectors of the 360 degree spectrum. Further manipulations of the pairs of data words provide a coarse phase measurement, being some integral multiple of .pi./2, and a fine phase correction factor less than or equal to .pi./4 radians. The coarse phase measurement is combined with the fine phase correction factor. The sum is differentiated and demodulated, yielding the original information signal.

Abstract: A trunked communication system utilizes talkgroup synchronization for roaming communication units. By automatically matching the communication unit's talkgroup in a first area-wide system with an talkgroup in a second area-wide system, the communication system facilitates rapid association with a desired talkgroup.

Abstract: A clock recovery circuit for a digital TDM mobile radio transceiver is disclosed. In the "acquisition mode", a first phase-locked loop is configured to acquire synchronization with the input data signal, and a second phase-locked loop is coupled to the first PLL's output signal, thereby providing the recovered clock signal. The controller monitors the transmit control line and the received signal strength so as to switch the clock recovery circuit into a second configuration during a TDM transmit burst or a received signal fade. In this "hold mode", the second PLL is configured to free-run within a specified tolerance, while the first PLL is coupled to the second PLL's output signal. The controller maintains this "hold" configuration until the received signal is again present, and until the first PLL again acquires synchronization to the input data signal.