How Height Above Ground Affects
Small Transmitting Loop Antennas
Ground reflections affect the antenna pattern and gain of a small transmitting loop antenna. I used computer simulations of a typical Amateur Radio HF loop to learn the effect of varying the height above ground. The results are in the July/August 2018 issue of QEX . I used an NEC-2 model in EZNEC  for a vertical 1 m diameter loop of 10 mm (3/8 inch) copper tubing located above “good” ground. The location of the resonating capacitor also affects the pattern and gain, so I simulated two configurations—with the tuning capacitor at the top or bottom of the vertical loop.
The antenna patterns described in the article are available on the ARRL website . (Neither membership nor subscription is required.) In the figures, h is the center height in meters.
1. P. DeNeef, AE7PD, “Effects Due to Ground For Small Transmitting Loop Antennas.” QEX, July/August 2018, pp 15-17.
2. Roy Lewallen, W7EL, EZNEC Antenna Simulation Program, www.eznec.com.
3. ARRL QEXfiles, July/August 2018, www.arrl.org/QEXfiles.
Peter DeNeef, AE7PD, is an Extra Class amateur radio operator in the USA. This website has no ads or conflicts of interest.
Email: HamRadioAndVision "at" gmail "dot" com.