Design of Arbitrarily Shaped Planar Microstrip Antenna Arrays with Improved Efficiency

Table 3

The performance of the circular array.

Frequency; (GHz)	Simulated								Measured
	Regular design				Irregular design				Irregular deign
	Gain; (dBi)	𝜂eff	X-Pol.; (dB)	S.L.L; (dB)	Gain; (dBi)	𝜂eff	X-Pol.; (dB)	S.L.L; (dB)	Gain; (dBi)	𝜂eff	S.L.L.; (dB)
12.25	29.3	49.7%	≤−48	≤−13.7	30.4	63.0%	≤−45	≤−13.7	30.1	58.8%	≤−13.2
12.50	29.4	48.1%	≤−48	≤−13.9	30.5	61.9%	≤−43	≤−14.2	30.3	59.2%	≤−14.1
12.75	29.5	47.3%	≤−44	≤−13.7	30.5	59.5%	≤−40	≤−13.6	30.3	55.3%	≤−13.8