To provide a high-frequency transmission line and an antenna device, having a reduced insertion loss over a wide frequency range, by making the cutoff frequency of the high-frequency transmission line higher than the conventional structure.
The antenna device is connected to a first end FP of a high-frequency transmission line 101, and a connector is connected to a second end SP. The characteristic impedance Zb1 of a microstrip line MSL is higher than the characteristic impedance of strip lines SL1, SL2, and the characteristic impedance Zb2 of the coplanar line CPL is higher than the characteristic impedance of the strip line SL2. Accordingly, there is produced a standing wave having a maximum voltage (loop of voltage intensity distribution) at the position of the microstrip line MSL and the position of the coplanar line CPL at a certain frequency. Namely, a 3/4 frequency resonance becomes a fundamental mode (harmonic wave of the lowest order). Thus, with a high cutoff frequency of the high-frequency transmission line, the signal insertion loss is suppressed low over a wide frequency range.
SASAKI SATOSHI
JP2007123740A | 2007-05-17 |
Next Patent: BROADCAST SIGNAL RECEIVER AND BROADCAST SIGNAL RECEIVING METHOD