Low noise lumped parameter active receiving antenna

United States Patent m

Naito

IUIIIIIIIIIIIIIIIIIIIIIIIIIIIII1IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

US005172126A

Patent Number: 5,172,126 [45] Date of Patent: Dec. 15,1992

[54] LOW NOISE LUMPED PARAMETER ACTIVE RECEIVING ANTENNA

[75] Inventor: Michiko Naito, Tokorozawa, Japan

[73] Assignee: Kabushiki Kaisha ENU ESU, Tokyo, Japan

[21] Appl. No.: 477,868
[22] PCT Filed: Aug. 7,1989
[86] PCT No.: PCT/JP89/00806

§ 371 Date: Apr. 9,1990

§ 102(e) Date: Apr. 9, 1990 [87] PCT Pub. No.: WO90/01814

PCT Pub. Date: Feb. 22,1990

[30] Foreign Application Priority Data

Aug. 12, 1988 [JP] Japan 63-200211

[51] Int. CI.' H01Q 1/26

[52] U.S. CI 343/701; 343/749

[58] Field of Search 343/701, 749; 455/293,

455/291, 341

[56] References Cited

U.S. PATENT DOCUMENTS

2.977,551 3/1961 Gibson et al 343/701

3,386.033 5/1968 Copeland et al 343/701

3,703,685 11/1972 Simopoulos et al 343/701

3,714,659 1/1973 Finnan 343/701

3,774,218 11/1973 Fowler 343/701

4,115,778 9/1978 Snow 343/701

5,019,830 5/1991 Harada 343/701

OTHER PUBLICATIONS

Tooley et al.; "Active Receiving Antenna", Practical Wireless, Mar. 1981, vol. 57, No. 3, pp. 52-56.

Primary Examiner—Rolf Hille

Assistant Examiner—Hoanganh Le

Attorney, Agent, or Firm—Lowe, Price, LeBlanc &

Becker

[57] ABSTRACT

A small, relatively wide-bandwidth, active antenna is usable in a wide range of applications spanning the VLF and SHF bands. The antenna is capable of receiving relatively weak radio frequency signals having a signal strength below that detectable using conventional passive antennas. The antenna includes a lumped constant element forming an electric wave receiving part, and a high impedence amplifier having input terminals connected via leads having a short electrical wavelength at the design frequency, to corresponding ends of the lumped constant element. Output terminals of the antenna are connected to a receiver to provide a small, high sensitivity, active antenna.

7 Claims, 4 Drawing Sheets