Low noise amplifier for ultra wide band

• US 20060170502A1
• Filed: 01/23/2006
• Published: 08/03/2006
• Est. Priority Date: 02/01/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-gug, Cha, Choong-Yul, Kim, Hoon-tae
• Granted Patent: US 7,616,061 B2
• Time in Patent Office: Days
• US Class Current: 330/295
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/26 Modifications of amplifiers to reduce influence of noise generated by amplifying elements
• CPC Class Codes: H03F 1/42 Modifications of amplifiers to extend the bandwidth
• CPC Class Codes: H03F 1/483 with field-effect transistors
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/36 the amplifier comprising means for increasing the bandwidth
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 2200/39 Different band amplifiers are coupled in parallel to broadband the whole amplifying circuit
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/345 with field-effect devices H03F3/347 takes precedence

Abstract

A low noise amplifier (LNA) for ultra wide band recives and amplifies identical RF signals in different frequency bands, and includes more than one pair of narrow band LNAs coupled in parallel, and a load circuit which increases load impedance of the entire circuit of the narrow band LNAs. The LNA can not only amplify the RF signal in the UWB but also obtain the low noise and the high gain that are features of the conventional narrow band LNA.

Claims

1. A low noise amplifier (LNA) for ultra wide band (UWB), comprising:

more than one pair of narrow band LNAs which is coupled in parallel, and receives and amplifies identical RF signals in different frequency bands; and

a load circuit which increases load impedance of the entire circuit of the narrow band LNAs.

2. The low noise amplifier of claim 1, wherein the narrow band LNAs each include an amplifying element and a pair of inductors which is connected to a source and a gate of the amplifying element respectively.

3. The low noise amplifier of claim 2, wherein the amplifying element is one of an NMOS transistor, a high electron mobility transistor (HEMT), and a bipolar transistor.

4. The low noise amplifier of claim 2, wherein the amplifying element of each narrow band LNA is connected to a common-gate amplifying element which forms a cascode amplifier together with the amplifying element, and the common-gate amplifying element has a common gate input.

5. The low noise amplifier of claim 4, wherein the load circuit is positioned between the common-gate amplifying elements, and includes a load resistor, an inductor, and a capacitor that are connected in parallel.

6. The low noise amplifier of claim 5, further comprising:

a buffer amplifying element which includes the load circuit located between a gate and a drain of the buffer amplifying element.

7. A low noise amplifier (LNA) for ultra wide band (UWB), comprising:

a plurality of narrow band LNAs coupled in parallel, wherein each narrow band LNA receives an identical RF signal and amplifies the RF signal in different frequency bands; and

a load circuit which increases load impedance of the entire circuit.

8. The low noise amplifier of claim 7, wherein each narrow band LNA comprises:

an amplifying element;

an inductor connected to a source of the amplifying element; and

an inductor connected to a gate of the amplifying element.

9. The low noise amplifier of claim 8, wherein the amplifying element is one of an NMOS transistor, a high electron mobility transistor (HEMT), and a bipolar transistor.

10. The low noise amplifier of claim 8, wherein each amplifying element is fabricated in a different size designed to amplify a different frequency band.

11. The low noise amplifier of claim 8, wherein the inductor connected to the source of the amplifying element and the inductor connected to the gate of the amplifying element are sized to provide a 50 Ω

input impedance for each narrow band LNA.