Radio signal switching system employing dielectric rod antennas

• US 4,053,894 A
• Filed: 03/20/1975
• Issued: 10/11/1977
• Est. Priority Date: 03/21/1974
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Beckmann, Oskar
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/560,404
• Time in Patent Office: 936 Days
• Field of Search: 343/785, 343/786, 343/783, 343/789, 343/817, 343/767, 343/769, 343/770, 343/776, 343/771, 343/775, 343/225, 343/226, 343/227, 343/228, 340/171 A
• US Class Current: 343/785
• CPC Class Codes: H02M 1/088 for the simultaneous control of series or parallel connected semiconductor devices

Abstract

A circuit arrangement for the wireless transmission of a control signal to the control path of a controllable semiconductor valve is disclosed. More particularly, in order to avoid corona discharges at the receiving antenna of the circuit, the latter antenna is constructed in the form of a high-frequency radiator which is comprised of at least partially electrically nonconductive material.

Claims

1. A transmission arrangement for the transmission of a control signal to each control path of a number of controllable semiconductor valves in a static high-voltage converter and for firing said valves, comprising:

a. a high-frequency transmitter for emitting high-frequency electromagnetic radiation which is modulated in dependence upon said control signal;

b. a plurality of high-frequency receivers located at some distance from said transmitter, each of said receivers being associated with one of said valves and each including a demodulator whose output is fed as a firing signal to the control path of the associated valve; and

c. a number of receiving antennas for receiving said high-frequency electromagnetic radiation, each receiving antenna being associated with one of said plurality of high-frequency receivers, each receiving antenna having a front part in the form of a cylindrical rod tapered along its longitudinal axis, said cylindrical rod having its smaller end pointed in the direction of the transmitted high-frequency electromagnetic radiation which it is to receive and said cylindrical rod consisting of material which is electrically non-conductive, and each receiving antenna having a rear part including coupling means for coupling the high-frequency electromagnetic radiation traveling along said cylindrical rod to the associated high-frequency receiver, a metal plate being disposed at the larger end of said rod, such that the normal to said plate is aligned with the radiation direction of said transmitter, said plate having a slot whose height is equal to half a wavelength of said radiation when said radiation is in said rod and whose width is substantially smaller than said half a wavelength, whereby the receiving antenna will not promote electrical discharges which would otherwise result because of the large potential difference between individual semiconductor valves and between a semiconductor valve and ground.

2. An arrangement in accordance with claim 1 in which each of said antennas has a length, as measured in the direction of radiation of said transmitter, which is such that said radiation upon traveling along the cylindrical rod to said coupling means experiences a phase shift of at least 180°

.

3. An arrangement in accordance with claim 1 in which said larger end is partially brought through said slot.

4. An arrangement in accordance with claim 1 in which said rod comprises a plastic material.

5. An arrangement in accordance with claim 4 in which said plastic material is polyfluoroethylene.

6. An arrangement in accordance with claim 4 in which said rod further includes metal particles, said particles being admixed with and finely distributed through said plastic material.

7. An arrangement in accordance with claim 6 in which said metal particles comprise gold dust.

8. An arrangement in accordance with claim 6 in which said metal particles comprise silver dust.