Signal receiver having wide band amplification capability

• US 7,212,749 B2
• Filed: 03/15/2005
• Issued: 05/01/2007
• Est. Priority Date: 12/15/1998
• Status: Expired due to Fees

• Current Assignee: IXYS Intl Limited (Littelfuse Incorporated)
• Original Assignee: ZiLOG Incorporated (Littelfuse Incorporated)
• Inventors: Hamilton, T. Allan, Grace, Alan
• Primary Examiner(s): Phan, Hanh
• Application Number:
  US11/080,161
• Publication Number:
  US 20050158053A1
• Time in Patent Office: 777 Days
• Field of Search: 398/202, 398/135, 398/136, 398/137, 398/209, 398/128, 398/210, 398/213, 398/130, 398/214, 398/115, 398/133, 330/135, 330/136, 330/308, 330/59, 330/60, 250/214.A, 250/214.R, 250/214.AG, 250/214.LA, 375/316, 375/317, 375/318, 455/130
• US Class Current: 398/202
• CPC Class Codes: H04B 10/693 Arrangements for optimizing the preamplifier in the receiver

Abstract

An Improved Signal Receiver Having Wide Band Amplification Capability is disclosed. Also disclosed is a receiver that is able to receive and reliably amplify infrared and/or other wireless signals having frequency bandwidths in excess of 40 MHz. The receiver of the present invention reduces the signal-to-noise ratio of the received signal to ⅕^th of the prior systems. The preferred receiver eliminates both the shunting resistor and the feedback resistor on the input end by amplifing the signal in current form. Furthermore, the receiver includes transconductance amplification means for amplifying the current signal without the need for Cascode stages. Finally, the receiver includes staged amplification to amplify the current signal in stages prior to converting the signal into a voltage output.

Claims

1. A device comprising:

a receiver of a wireless signal, wherein the receiver outputs a current signal onto a node;

a first transistor with a drain, wherein the node is coupled to the drain of the first transistor, wherein the first transistor generates a feedback current, wherein the feedback current is dependent on the magnitude of the current signal, and wherein the first transistor is not cascode-connected;

a second transistor with a source and a drain, wherein the node is coupled to the source of the second transistor; and

a current mirror that is coupled to the drain of the second transistor, wherein the first transistor amplifies the current signal, wherein the device converts the amplified current signal to a voltage signal, and wherein the device does not include a feedback resistor.

2. The device of claim 1, wherein the receiver outputs the current signal in response to receiving a radio frequency signal.

3. The device of claim 1, wherein the device is part of a cellular phone.

4. The device of claim 1, wherein the receiver outputs the current signal in response to receiving an infrared radiation signal incident on a photodiode, wherein the infrared radiation signal has a level and the current signal has a magnitude, and wherein the magnitude of the current signal is dependent on the level of the infrared radiation signal.

5. The device of claim 1, wherein the first transistor exhibits a bias voltage, and wherein the bias voltage is dynamically adjustable such that the first transistor operates in a weak inversion range.

6. The device of claim 1, wherein the first transistor functions as a transimpedance amplifier.

7. The device of claim 1, wherein the current signal is amplified in stages prior to the device converting the amplified current signal to the voltage signal.

8. The device of claim 1, wherein the node exhibits an impedance, and wherein the first transistor reduces the impedance.

9. The device of claim 1, wherein the current signal is amplified over a frequency bandwidth in excess of 40 MHz.

10. A method comprising:

(a) receiving a wireless signal;

(b) generating a current signal in response to receiving the wireless signal, wherein the wireless signal has a level and the current signal has a magnitude, and wherein the magnitude of the current signal is dependent on the level of the wireless signal;

(c) amplifying the current signal to generate an amplified current signal, wherein the current signal is amplified in stages, wherein the current signal is amplified without using a feedback resistance, wherein the current signal is amplified using a transistor, wherein the transistor exhibits a bias voltage, and wherein the bias voltage is dynamically adjustable such that the transistor operates in a weak inversion range; and

(d) converting the amplified current signal to a voltage signal.

11. The device of claim 10, wherein the wireless signal is a radio frequency signal.

12. The device of claim 10, wherein the wireless signal is an infrared radiation signal, and wherein the wireless signal is received onto a photodiode.

13. A device comprising:

a receiver that outputs a current signal onto a node in response to receiving a wireless signal, wherein the wireless signal has a level and the current signal has a magnitude, wherein the magnitude of the current signal is dependent on the level of the wireless signal, and wherein the node exhibits an impedance;

a transistor with a source and a drain, wherein the node is coupled to the source of the transistor;

a current mirror that is coupled to the drain of the transistor; and

means for reducing the impedance at the node and for amplifying the current signal, wherein the device converts the amplified current signal to a voltage signal.

14. The device of claim 13, wherein the means generates a feedback current, wherein the feedback current is dependent on the magnitude of the current signal, and wherein the transistor is not cascode-connected.

15. The device of claim 13, wherein the means amplifies the current signal over a bandwidth, further comprising:

means for increasing the bandwidth over which the current signal is amplified.

16. The device of claim 13, wherein the means does not employ a feedback resistance.

17. The device of claim 13, wherein the means does not employ a cascode-connected transistor.

18. The device of claim 13, wherein the means comprises a transimpedance amplifier.

19. The device of claim 13, wherein the means amplifies the current signal in stages prior to converting the amplified current signal into the voltage signal.

20. The device of claim 13, wherein the means employs neither a shunt resistor nor a feedback resistor.