| 摘要 |
PROBLEM TO BE SOLVED: To easily perform impedance matching for ASK(amplitude shift keying) modulation in a desired frequency with high reproducibility and also to facilitate manufacturing excellent in mass-productivity. SOLUTION: This pulse modulator is provided with a circulator comprising of a plurality of mode suppressors 1a to 1c which are arranged almost radially at two ferrite discs 2 arranged oppositely to each other in the inner face of a parallel planar conductor, transmit an electromagnetic wave of an LSM mode and interrupt an electromagnetic wave of an LSE mode, and impedance matching members 4 arranged at one end face of each of the mode suppressors 1a to 1c, a switch Sp for pulse modulation having a Schottky barrier diode 7 is provided on the other end face of the mode suppressor 1b so that the bias voltage applied direction of the barrier diode 7 may coincide with the electric field direction of the LSM mode electromagnetic wave, and a distance from the end of the ferrite discs 2 to the Schottky barrier diode 7 is defined as about nλ/2 (n is >=1 integer and λ is wavelength of high frequency signal). |
