Dual-Band Miniature Coupled Double Loop GPS Antenna Loaded With Lumped Capacitors and Inductive Pins

A miniature coupled double loop (CDL) antenna for dual-band GPS application is presented. The antenna layout employs lumped capacitors and inductive pins over a moderately high permittivity Rogers TMM10i (ε
r
= 9.8) substrate to concurrently achieve the goals of size miniaturization, high radiation efficiency, and proper spacing of L2 and L1 band resonance frequencies. For performance verification, an antenna prototype has been fabricated over a 500 mil thick substrate with an overall L2 band size of λ
₀
/8.8×λ
₀
/8.8×λ
₀
/19.4. The antenna operates with > 50% less area as compared to a conventional L2 band patch realized over the same substrate. The measured broadside RHCP realized gains are 4.9 and 3.1 dB over a 24"×24" ground plane with 26 and 35 MHz 3 dB realized gain bandwidths at the L2 and L1 bands, respectively. The antenna operates with 82% L2 and 72% L1 band measured radiation efficiencies.