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 [1]. I used an NEC-2 model in EZNEC [2] 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 [3]. (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.

 

Author Information

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.

8/9/2018