| 摘要 |
PROBLEM TO BE SOLVED: To provide a microstrip antenna capable of having an excellent axial ratio in a desired frequency band while having a smaller size comparing to conventional ones.SOLUTION: A Wilkinson coupler part 24 is a circuit for dividing an input signal from an input terminal 26 into two signals, and includes two &pgr; type filters 24a, 24b and a resistor 24c. The &pgr; type filters 24a and 24b are mutually connected in parallel and the resistor 24c is connected between output terminals of the &pgr; type filters 24a and 24b. The cutoff frequencies of the &pgr; type filters 24a and 24b are set at the center frequency of GNSS frequency band, which is approximately 1590 MHz. A phase shift part 25 is connected to one output terminal of the Wilkinson coupler part 24. The phase shift part 25 is a &pgr; type filter and its cutoff frequency is set at a frequency of the center of GNSS frequency band, which is approximately 1590 MHz. |
