| 摘要 |
A dual band helical antenna (300, 400, 500) with wide bandwidth includes at straight section (31, 41, 51) and a helical tail section (32, 42, 52) having a first and a second coil length, respectively. The straight section (31, 41, 51) has a signal feed point (30, 40, 50) located at a lower end thereof being connected to a signal source for feeding in an antenna signal. The first coil length determines a high-frequency resonant frequency of the dual band helical antenna (300, 400, 500), and a total length of the first and the second coil length determines a low-frequeney resonant frequency of the dual band helical antenna (300, 400, 500). The straight section (31, 41, 51) includes a diametrically expanded section (312, 412, 512) to increase a high-frequency bandwidth of the dual band helical antenna (300, 400. 500). |
