Accession Number : AD0903919

Title :   Non-Sampling UHF Same Frequency Repeater.

Descriptive Note : Supplement to Final rept.,

Corporate Author : EATON CORP DEER PARK NY AIL DIV

Personal Author(s) : Hertz, Robert F.

Report Date : MAR 1972

Pagination or Media Count : 60

Abstract : The UHF Same Frequency Repeater suffered from low usable isolation because of the limitations in manually tuning the matching network of a hybrid to equal the constantly varying impedance of an antenna. Operation of the repeater was further hampered by the adjustments necessary to accommodate band switching. An Automatic Impedance Matching (AIM) network was developed to continuously adjust the impedance of the matching network to automatically maintain a high isolation between the transmitter and receiver ports of the hybrid. A common RF switch was also designed as part of this program so that channel switching could be accomplished with only one control, without the need to make readjustments. RFI due to incomplete transmitter shutdown was eliminated by the addition of a coaxial relay. Other sources of RFI were eliminated by replacing most RF cables with double-shielded coax.

Descriptors :   (*RADIO REPEATERS, ULTRAHIGH FREQUENCY), (*COMMUNICATION AND RADIO SYSTEMS, RADIO REPEATERS), IMPEDANCE MATCHING, AUTOMATIC, RADIOFREQUENCY INTERFERENCE, TRANSMITTER RECEIVERS, ELECTROMAGNETIC SHIELDING, COAXIAL CABLES, POWER SUPPLIES, FIELD EFFECT TRANSISTORS, AMPLITUDE MODULATION, POWER AMPLIFIERS, ANTENNAS.

Subject Categories : Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE