Accession Number:

ADA159070

Title:

Effect of Antenna Impedance Mismatch on the Signal-to-Noise Ration of a Radio Receiving System.

Descriptive Note:

Final rept.,

Corporate Author:

MITRE CORP BEDFORD MA

Personal Author(s):

Report Date:

1985-07-01

Pagination or Media Count:

170.0

Abstract:

The noise factor of linear two-port networks are derived for several networks of interest, including those of a passive transmission line and of an active receiver, whose source impedance may be mismatched to the characteristic impedance of the line. It is shown that a large impedance mismatch at the antenna-transmission line interface of a radio receiving system can cause a significant increase in the system internal noise factor more than a 50 dB increase for a voltage reflection coefficient of 09999. Numerical results are presented for a VHF-FM radio receiving system with an electrically-short monopole antenna. In the absence of a matching network, the limiting noise of the system is generated within the system by the transmission line and receiver and can be more than 20 dB larger than the external man-made noise. With a matching network, the limiting noise of the system is external man-made noise. Keywords include Antenna, Impedance Mismatch, Linear Two-Port Networks, Noise Factor, Noise Figure, and Radio Receiving System.

Subject Categories:

  • Electrical and Electronic Equipment
  • Cybernetics
  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE