DE20022796U1

DE20022796U1 - Technique for reducing parasites in a loop antenna

Info

Publication number: DE20022796U1
Application number: DE20022796U
Authority: DE
Original assignee: Logitech Europe SA
Current assignee: Logitech Europe SA
Priority date: 1999-12-01
Filing date: 2000-11-30
Publication date: 2002-04-04
Anticipated expiration: 2010-12-01

Description

Der Beschreibungstext wurde nicht elektronisch erfaßt The description text was not recorded electronically

Der Beschreibungstext wurde nicht elektronisch erfaßtThe description text was not recorded electronically

Claims

1. Antenna circuit with:
a conductor at least for receiving or generating radiation information having a first loop segment and a second loop segment, each loop segment having an inner and an outer end and the conductor having an inductive reactance and a reactive voltage;
a first capacitive reactance connected in series between the inner ends of the first and second loop segments of the conductor; wherein the first capacitive reactance to provide an initially reactive voltage that is substantially the same in size and substantially 180 degrees out of phase with a first component of the reactive voltage across the conductor, leaving a residual component of the reactive voltage across the conductor ; and
a second capacitive reactance to provide a second reactive voltage that is substantially the same in size and substantially 180 degrees out of phase with the residual component of the reactive voltage across the conductor, the second capacitive reactance across the outer ends of the first and second loop segment is connected.

2. Antenna circuit according to claim 1, characterized in that the length of the first loop segment is determined by the following formula:
x = [1 - (w2.La.Cx) / 2] .L
where x is the length of the first loop segment, L is the total length of the conductor, w = 2nd PI operating frequency, La is an inductor value connected to the conductor and Cx is a capacitor value connected to the first capacitive reactance.

3. Loop antenna circuit with:
a conductor at least for receiving and generating radiation information having a first loop segment and a second loop segment, each loop segment having inner and outer ends, and the conductor having an inductive reactance and a reactive voltage;
a first capacitive reactance for providing a first reactive voltage that substantially extinguishes a first component of the reactive voltage of the conductor, leaving a residual component of the reactive voltage of the conductor, the first capacitive reactance being serial between the inner ends of the first and second Loop segment is connected;
a second capacitive reactance connected in series along the outer end of the first loop segment of the conductor;
a third capacitive reactance connected in series along the outer end of the second loop segment of the conductor; and
a fourth capacitive reactance, which is connected via the serial combination of the second capacitive reactance, the first loop segment, the first capacitive reactance, the second loop segment and the third capacitive reactance.

4. The circuit of claim 3, wherein the first capacitive reactance is substantially the same one half of the inductive reactance and the third capacitive reactance essentially are equal to a quarter of the inductive reactance.

5. Loop antenna circuit with:
a conductor at least for receiving or generating radiation information, the conductor having a reactive voltage and the conductor comprising a first loop segment and a second loop segment; and
a capacitive reactance with a reactive voltage that extinguishes a portion of the reactive voltage of the conductor, the capacitive reactance between the first loop segment and the second. Loop segment is serially coupled.

6. The circuit of claim 5, wherein the reactive voltage of the capacitive reactance in essentially the same and out of phase by 180 ° to a reactive voltage the first or the second loop segment.

7. Loop antenna circuit with:
a conductor with a first loop segment and a second loop segment;
a polarization changing device which is connected in series between the first loop segment and the second loop segment in order to reduce a reactive voltage of the conductor.

8. The circuit of claim 7, wherein the polarization changing device is a condenser goal is.

9. Loop antenna circuit with:
a conductor having a first loop turn and a second loop turn formed adjacent to the first loop turn; and
a polarization changing device connected in series between the first and second loops to reduce a reactive voltage difference between the two turns.

10. The circuit of claim 9, wherein the polarization changing device is a condenser goal is.

11. The circuit of claim 9, wherein the first and second loop turns that be are arranged adjacent to each other, are formed through a circuit board.

12. Loop antenna circuit with: a conductor with multiple loop segments that form a length of the conductor; and a number of capacitors, each capacitor between a corresponding one Pair of loop segments is serially coupled and each capacitor is a right has active voltage that is part of a reactive voltage on the conductor extinguished.

13. Loop antenna circuit according to one of claims 7 to 12, wherein the loops on Barrier circuit in at least one cordless input device or a cordless sen receiving unit of a cordless device is used.

14. Loop antenna circuit according to one of claims 7 to 12, wherein the loops on circuit in at least one cordless mouse, a cordless mouse receiver ger, a cordless keyboard or a cordless keyboard receiver is used.