Compact dual-band circularly polarized antenna for GPS/ETC operation on vehicles

A new integration design of two circularly polarized (CP) antennas for global positioning system (GPS) and electronic toll collection system (ETC) is presented. A probe-fed earner-truncated square microstrip antenna, which is a resonant-type structure, is used for GPS operation at 1575 MHz. For achieving broadband CP operation in the 5800 MHz band (5725-5875 MHz) for ETC operation, a monopole-fed CP loop antenna, which is a traveling-wave-type structure, is applied. The two antennas are integrated in a compact configuration in the proposed design and are suitable for GPS and ETC operations on vehicles. (C) 2004 Wiley Periodicals, Inc.