NEGATIVE RESISTANCE ANTENNA AMPLIFIER ARRANGEMENT

• US 3,633,109 A
• Filed: 10/21/1968
• Issued: 01/04/1972
• Est. Priority Date: 10/21/1967
• Status: Expired due to Term

• Current Assignee: Hansrichard Schulz
• Original Assignee: Hansrichard Schulz
• Inventors: Schulz, Hansrichard
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Leibowitz, Barry
• Application Number:
  US04/769,144
• Time in Patent Office: 1,170 Days
• Field of Search: 179/17T,17HF,17U 325/373,374,375,384,318,365 330/4.5,4.9,61A 331/132,3,4
• US Class Current: 455/151.3
• CPC Class Codes: H03F 1/34 Negative-feedback-circuit arrangements with or without positive feedback H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence ; for rejection of common mode signals H03F3/45479
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/191 Tuned amplifiers H03F3/193, H03F3/195 take precedence

Abstract

An oscillator circuit is kept at a predetermined stableoperating point below the onset of oscillations by highresistance feedback in the emitter circuit. The tuned circuit of the oscillator has one winding of a transformer whose second winding is connected either in series between the antenna and the receiver, or in parallel with the receiver. The impedance seen looking into the second winding is a negative resistance.

Claims

1. Receiving arrangement, comprising, in combination, antenna means;

a negative-resistance circuit means connected to said antenna means, said negative-resistance circuit means comprising oscillator circuIt means having an amplifier element, said amplifier element having a first and second output electrode and a control electrode;

high-resistance passive feedback means connected to said first output electrode for maintaining the operating point of said amplifier element at a predetermined stable point below onset of oscillations; and

high-frequency voltage divider means connected to said amplifier element for furnishing additional feedback in such a manner that the operating point of said amplifier element lies in a region of relatively small changes in amplification; and

receiver means connected to said negative-resistance circuit means.

2. An antenna arrangement as set forth in claim 1, further comprising four-terminal amplifier circuit means having a pair of input terminals connected to said interconnected antenna and negative-resistance circuit means, said four-terminal amplifier circuit means further having a pair of output terminals;

and receiver means connected to said pair of output terminals of said four-terminal amplifier circuit means.

3. An antenna arrangement as set forth in claim 1, further comprising receiver means connected to said interconnected antenna means and negative-resistance circuit means.

4. Antenna arrangement as set forth in claim 3 wherein said circuit means is connected in series between said antenna means and said receiver means.

5. Antenna arrangement as set forth in claim 3 wherein said antenna means, said negative-resistance circuit means and said receiver means are connected in parallel to each other.

6. Antenna arrangement as set forth in claim 1 wherein said voltage-divider means comprise a first and second capacitor, each of said capacitor having a leakage resistance, the value of said leakage resistance in parallel to said control electrode of said amplifier element being small compared to the input impedance of said control electrode.

7. An antenna arrangement as set forth in claim 1, wherein said amplifier element is a transistor and wherein said first output electrode is the emitter of said transistor.

8. Receiving arrangement, comprising, in combination, antenna means;

a negative-resistance circuit means connected to said antenna means, said negative-resistance circuit means comprising oscillator circuit means having an amplifier element, said amplifier element having a first and second output electrode and a control electrode;

high-resistance feedback means connected to said first output electrode for maintaining the operating point of said amplifier element at a predetermined stable point below onset of oscillations, said oscillator circuit further comprising tuning means for the remote tuning thereof and receiver means connected to said negative-resistance circuit means.

9. An antenna arrangement as set forth in claim 8, wherein said oscillator circuit further comprises transformer means having a first winding connected in parallel with said tuning means and a second winding, inductively coupled to said first winding, connected to said antenna means and said receiver means.

10. Antenna arrangement as set forth in claim 8 wherein said tuning means comprise capacitive tuning means.

11. Antenna arrangement as set forth in claim 10 wherein said capacitive tuning means comprise capacitive diodes.