RECEIVING ANTENNA FOR MINIATURE RADIO RECEIVER

• US 3,736,591 A
• Filed: 10/04/1971
• Issued: 05/29/1973
• Est. Priority Date: 10/30/1970
• Status: Expired due to Term

• Current Assignee: Larry W. Rennels, William J. Wilson
• Original Assignee: Larry W. Rennels, William J. Wilson
• Inventors: Rennels, Larry W., Wilson, William J.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/186,154
• Time in Patent Office: 603 Days
• Field of Search: 343/702,718,748 325/354,352
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

Receiving antenna for miniature radio receiver formed by conducting U-shaped member having substantially parallel elongated arms which form sides of the housing of the receiver and a connecting portion which forms one end of the housing. When the receiver is in the normal position for use, the arms are positioned vertically with the connecting portion at the top, and the U-shaped member acts as an inductive loop antenna to detect the H-field of the electro-magnetic wave. A reactance network, which is capacitive in the frequency range of interest, is connected to the open ends of the arms. The reactance network can be adjustable to tune the antenna for various frequencies, the antenna having been found suitable for use in the frequency range from 148 to 173 megacycles.

Claims

1. An antenna for a miniature radio receiver adapted to be carried on a person including in combination, a flat conductive member formed in a U-shaped configuration having first and second elongated substantially parallel arms and a portion connecting said arms, said arms having a length substantially greater than that of said connecting portion, said conductive member forming a Part of the housing of the receiver with said arms extending substantially vertical in the normal position of the receiver, and reactance means coupled to the ends of said arms opposite to said connecting portion, said reactance means presenting a capacitive reactance across said conductive member.

2. The antenna of claim 1 wherein said U-shaped conductive member forms an inductive loop antenna.

3. The antenna of claim 2 wherein said reactance means is adjustable to select the value of said capacitive reactance to tune said conductive member for reception of the H-field of an electro-magnetic wave.

4. The antenna of claim 1 wherein said reactance means includes an inductor and a pair of series connected capacitors connected in parallel with said inductor, said inductor having end terminals and an intermediate terminal, with one end terminal and said intermediate terminal being connected to said arms of said conductive member, and an output conductor connected to the junction of said capacitors.

5. The antenna of claim 4 wherein said inductor is variable for tuning said reactance means, and said one end terminal connected to said arm of said conductive member is connected to the ground potential of the receiver.

6. The antenna of claim 1 wherein said reactance means includes a plurality of parallel branches connected between said ends of said arms, one of said branches including a capacitor and another branch including a variable inductor for tuning the antenna for reception of waves of a particular frequency.

7. The antenna of claim 6 wherein said reactance means includes a parallel branch having a diode rendered conductive in response to a received wave which exceeds a predetermined strength.

8. An antenna for a miniature radio receiver adapted to be carried on a person with one side thereof in proximity to the person, including in combination, a flat conducting member formed in a U-shaped configuration having first and second elongated substantially parallel conducting arms and a conducting portion connecting said arms, said member forming a part of the housing of the receiver with said arms constituting at least parts of the opposite sides and said conducting portion constituting at least part of the top of the housing, said arms of said U-shaped conducting member extending vertically in the normal position of the receiver with one of said arms in proximity to the person, and reactance means coupled to the ends of said arms opposite to said connecting portion for deriving signals therefrom.

9. The antenna of claim 8 including spring biased contact means engaging said arms at the ends thereof opposite to said conducting portion for making electrical connections between said arms and said reactance network.

10. The antenna of claim 9 wherein said contact means engaging said one arm is connected to ground potential of the receiver.

11. The antenna of claim 10 wherein said reactance means includes an inductor and a pair of series connected capacitors connected in parallel with said inductor, said inductor having an end terminal connected to said contact means connected to said arm forming part of said one side of the housing and an intermediate terminal connected to said arm forming part of the opposite side of the housing.

12. The antenna of claim 11 wherein said inductor is variable to control the tuning of said reactance means and is adjusted so that the reactance means presents a capacitive reactance across said ends of said arms.

13. The antenna of claim 10 wherein said reactance means includes a plurality of parallel branches connected between said ends of said arms, with one branch including a capacitor, a second branch including an adjustable inductor and a third branch including a pair of series connected capacitors.

14. The antenna of claim 13 wherein one of said parallel branches includes rectifier means selectively rendered conductive in response to a received wave above a predetermined strength.

15. The anteNna of claim 8 wherein said reactance means is tuned so that said U-shaped conducting member forms a loop antenna for receiving the H-field of an electro-magnetic wave of a particular frequency.