Bypass low-noise amplifier (LNA) can be used in the base station receiver to improve the dynamic range. It is difficult to achieve both ultra low noise at LNA mode and maintain good linearity at bypass mode simultaneously. In this work, we present the best performance bypass LNA with 0.5 dB of noise figure (NF), 20 dB of gain at 1.95 GHz and high OIP3 of 35 dBm for both LNA and bypass mode. Fabricated in 0.25um GaAs E/D pHEMT process, the LNA is based on enhancement mode pHEMT cascode topology and the switches are designed with the depletion mode pHEMT.

1.5–2.7 GHz ultra low noise bypass LNA

This paper presents a wideband, fully integrated, low-noise amplifier with a noise figure of less than 0.5 dB. The device is fabricated in a 0.35 μm GaAs enhancement-mode pHEMT process because of its positive threshold voltage and superior noise performance. The amplifier is housed in a low-cost 2×2 mm2 8-pin QFN plastic package with internal gate biasing and input and output matching. To our knowledge, this work achieved the best result of reported combination of low noise figure, OIP3 (40 dBm), and Linearity Figure of Merit (LFOM) of 15dB at a frequency range of 1.5-2.7GHz for sub-0.5 dB NF LNA, and integrated power-down function for system control.

Ultra low-noise highly linear integrated 1.5 to 2.7 GHz LNA

This paper analyzed the impact of LNA performances on a modern receiver of a mobile base station Recent mobile communication systems, such as a LTE system, employs MIMO techniques, carrier aggregation, mutli-band frequencies, etc The transmitter on a mobile base station transmits broadband, high power, and multi-frequency signals The receiver on the base station employs high performance frequency selective filters to avoid the interference from the transmitter This paper investigated the relationship between the LNA performances, linearity and noise figure, and the receiver performances The investigation also indicated the high linearity LNA enables to decrease the required filter performances on the receiver, resulting in low cost and compact base station The above analysis and verification were performed by simulation and measurement with the fabricated GaN HEMT LNA

Impact of LNA Performances on Mobile Base Station Receiver

This paper presents the designing and implementation of Low Noise Amplifier for MRI (Magnetic Resonance Imaging) Scanner. MRI Scanner is widely used diagnostic tool which treat in the Diagnosis of Diseases and results non-invasive way of imaging [1] [2]. The RF MRI signal coming from receiving coil must be amplified for further Data-Processing. The Signal undergoes data processing must have low noise as well as desired gain, Thus SNR of MRI is foremost important. This is achieved by using Low noise amplifier (Pre-amplifier) at 1st stage of MRI Scanner Receiver. In this paper low noise amplifier is designed for 1.5T MRI Scanner, having noise figure 0.5–0.6 dB with gain greater than 20 dB at frequency of 63.87 MHz, Bandwidth is 5 MHz.

Design and implementation of low noise amplifier for MRI scanner

This paper presents a high linearity wide bandwidth low noise amplifier (LNA) MMIC with excellent noise figure. The amplifier topology is compromised of a single-stage cascode topology with inductive source degeneration of common-source device. This amplifier topology seems an attractive choice for applications requiring wide bandwidth, high gain, and high linearity. The design targets 700–900 MHz, 1700–2200 MHz, and 2500–2800 MHz frequency bands for GSM/WCDMA/LTE base station receiver applications. A single-stage amplifier is implemented in a high performance 0.25um InGaAs E/D-mode pHEMT technology and demonstrates a high gain and an excellent bandwidth along with a high-linearity. Additionally, an excellent noise performance is achieved demonstrating $< \pmb{0.6} \mathbf{dB}$ noise figure in 700–900 MHz frequency band while exhibiting $< \pmb{0.75}\ \mathbf{dB}$ noise figure in 1700–2200 MHz frequency band. A single-stage amplifier provides 20 dB of small-signal gain with excellent linearity of output $\mathbf{OIP}\pmb{3}\geq+\pmb{32.0}\mathbf{dBm}$ while requiring only 45 mA from a $\pmb{+5}\mathbf{V}$ supply.

A High Linearity Wide Bandwidth GSM/WCDMA/LTE Base Station LNA MMIC with Ultra Low Noise Figure

This paper presents a highly integrated, sub 0.5 dB noise figure (NF) low noise amplifier (LNA) targeting 700/900 MHz GSM/CDMA/LTE base station receiver and tower mount antenna (TMA) applications. The amplifier is realized using a GaAs pHEMT process, and is housed in a very small 2 × 2 mm2 low cost plastic surface mount DFN style package. State-of-the art noise performance of less than 0.5 dB NF is achieved through an innovative design methodology and circuit architecture which takes full advantage of the selected GaAs device technology. This work represents one of the best matched LNA noise figures reported to-date in this frequency band. In addition to very low noise performance, the amplifier simultaneously exhibits gain greater than 21 dB, excellent linearity, and is closely matched to 50 Ω at the input and output ports. Very wide bandwidth performance from 300 MHz to beyond 1400 MHz is demonstrated, and performance within this frequency range can be further enhanced through selection of specific off-chip components.

Rick Hooper

Papers

Wide bandwidth GSM/WCDMA/LTE base station LNA with ultra-low sub 0.5 dB noise figure