A Novel Wide-Beam Circularly Polarized Antenna for SDARS Applications

In this letter, a novel wide-beam circularly polarized (CP) antenna is presented for satellite digital audio radio service (SDARS) band (2320–2345 MHz), intended for application in portable terminals. This new antenna is comprised of four independent radiation units that are axial symmetrical around the center. The radiation unit is miniaturized by using a distributed capacitive load and a short point in its configuration. The antenna is excited by a compact four-way, quadrifilar power splitter, which is implemented by using microstrip phase shifter and couplers. Simulation results match well with the experimental ones, demonstrating a half-power beamwidth (HPBW) of 120
$^{\circ}$
, a 3-dB axial-ratio beamwidth of 180
$^{\circ}$
, and a good match at 2100–2400 MHz. The developed antenna is based on low-cost printed circuit board (PCB) technique and can be easily integrated with other microwave circuits.