| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulse modulator, preventing the deterioration of the workability of a circulator or the like due to leakage of electromagnetic waves and having proper ASK modulation characteristics. SOLUTION: The circulator composed, of a plurality of mode suppressors and arranged approximately radially to two ferrite plates and impedance matching members installed on one end faces of the mode suppressors, is mounted between parallel plate conductors arranged at an interval of half or smaller of the wavelength λ of the high-frequency signal. A switch for pulse modulation is secured on the other end faces of the mode suppressors, so that the bias-voltage application direction of a Schottky barrier diode coincides with the electric field direction of the electromagnetic waves of LSM mode. The distance from the ends of the ferrite plates to the Schottky barrier diode is set to be approximately nλ/2 (n represents an integer larger than 1 or equal to), and the planarity of the internal surfaces of the parallel plate conductors reaches 0.01 mm or less. |
