Impedance matching low noise amplifier having a bypass switch

• US 20040251960A1
• Filed: 07/21/2004
• Published: 12/16/2004
• Est. Priority Date: 11/08/2000
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Macedo, Jose A.
• Granted Patent: US 6,977,552 B2
• Time in Patent Office: Days
• US Class Current: 330/51
• CPC Class Codes: H03F 1/302 in bipolar transistor amplifiers H03F1/303, H03F1/305, H03F1/307 take precedence
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 3/191 Tuned amplifiers H03F3/193, H03F3/195 take precedence
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H03G 1/0088 using discontinuously variable devices, e.g. switch-operated

Abstract

An impedance matching low noise amplifier (“LNA”) having a bypass switch includes an amplification circuit, a bypass switching network and a match adjustment circuit. The amplification circuit has an amplifier input and an amplifier output, and is configured to receive a radio frequency (RF) input signal at the amplifier input and apply a gain to generate an amplified RF output signal at the amplifier output. The bypass switching network is coupled to a low-gain control signal and is also coupled between the amplifier input and the amplifier output. The bypass switching network is configured to couple the amplifier input to the amplifier output when the low-gain control signal is enabled in order to feed the RF input signal through to the RF output signal. The match adjustment circuit is coupled to the low-gain control signal and the RF input signal, and is configured to couple the RF input signal to an impedance when the low-gain control signal is enabled.

Claims

1. A low noise amplifier (LNA), comprising:

an amplification circuit having an amplifier input and an amplifier output, and configured to receive a radio frequency (RF) input signal at the amplifier input and apply a gain to generate an amplified RF output signal at the amplifier output;

a bypass switching network coupled to a low-gain control signal and also coupled between the amplifier input and the amplifier output, and configured to couple the amplifier input to the amplifier output when the low-gain control signal is enabled in order to feed the RF input signal through to the RF output signal; and

a match adjustment circuit coupled to the low-gain control signal and the RF input signal, and configured to couple the RF input signal to an impedance when the low-gain control signal is enabled.