AUTOMATIC ANTENNA COUPLER UTILIZING SYSTEM FOR MEASURING THE REAL PART OF THE COMPLEX IMPEDANCE OR ADMITTANCE PRESENTED BY AN ANTENNA OR OTHER NETWORK

• US 3,825,825 A
• Filed: 09/04/1973
• Issued: 07/23/1974
• Est. Priority Date: 02/02/1970
• Status: Expired due to Term

• Current Assignee: Carl M. Smolka
• Original Assignee: Carl M. Smolka
• Inventors: Smolka, Carl M.
• Primary Examiner(s): Krawczewicz, Stanley T.
• Application Number:
  US05/393,843
• Time in Patent Office: 322 Days
• Field of Search: 324/57R,57Q 325/174
• US Class Current: 324/649
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H03J 3/185 with varactors, i.e. voltage variable reactive diodes

Abstract

An automatic antenna coupler is described which includes a matching network having adjustable reactive elements. Control for these elements is provided by a system for detecting the real part of the complex impedance presented by the antenna or matching network. A logic and control system for adjusting the reactive elements is operated in accordance with the real part detector output so as to provide the desired impedance match.

Claims

1. A system for measuring the complex impedance or admittance presented by a network at an input port thereof, said system comprising, a. means responsive to the voltage and current components of a signal applied to said port for deriving a first output having an amplitude proportional to the phase difference therebetween, b. means responsive to said voltage component for deriving a second output proportional to the amplitude thereof, and c. means responsive to said first and second outputs for deriving a third output proportional to the ratio thereof, the ratio of said first output with respect to said second output providing said third output corresponding to the real part or of said complex impedance and the ratio of said second output with respect to said first output corresponding to the real part of said complex admittance.

2. The invention as set forth in claim 1 wherein said first output providing means includes a balanced mixer which provides as said first output a d.c. signal whose amplitude is proportional to said phase difference whereby said first output is alsO proportional to the component of said current which is in phase with said voltage.

3. The invention as set forth in claim 1 wherein said second output providing means includes an amplitude detector which provides as said second output a d.c. signal whose amplitude is proportional to said voltage.

4. The invention as set forth in claim 1 wherein said third output providing means includes separate circuits for translating said first and second outputs into the fourth and fifth outputs respectively proportional to the logarithms thereof, and derives as said third output the difference of the amplitudes between said fourth and fifth outputs.

5. The invention as set forth in claim 1 further comprising a. means for shifting the phase of said voltage component 90*, b. means responsive to said phase shifted voltage component and said current component as set forth in subparagraphs (a) - (c) for deriving a fourth output corresponding to the imaginary part of said complex impedance or admittance, and c. display means responsive to said third and fourth outputs for depicting a vector representing said complex impedance or admittance.

6. The invention as set forth in claim 5 wherein said display means is an oscilloscope, said third output being applied to the X input thereof and said fourth output being applied to the Y input thereof.