Johnson and Jasik in _Antennas_ refer to TV receiving loops in their chapter on TV antennas, chapter 29. The loop antenna in general is discussed in Chapter 5. A loop and plane reflector is also discussed.
Amateur experience with the one wavelength loop (search for "quad" antennas) suggests it has about 2 dB gain compared to a dipole. This is in line with the analysis of a one wavelength loop as two dipoles spaced the diameter of the loop. Adding 2 dB to the received signal and assuming a dipole otherwise would seem to me a good approximation -- where the loop is a wavelength in circumference. Elsewhere, things are less simple. At a *half* wavelength, for example (250 MHz?), the loop impedance may be 10,000 ohms, and the reactance off resonance around this is high as well. If you need exact numbers, you might compare a loop with an antenna whose AF is known. Simple UHF loops are, however, not usually installed with good engineering practice in mind, are terminated with lengths of 300 ohm twinlead on baluns of unknown quality, connected to apparatus of indifferent specifications. Also, 200-1000 Mhz is rather wider than these loops are designed for. Have fun! Cortland This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
