Columbia University

Technology Ventures

Field-programmable low noise amplifier for linearity enhancement

Technology #cu14321

To amplify desired signals while minimizing noise in handheld wireless devices, low noise amplifiers (LNA) are typically placed after the antennas. However, in addition to the weak signal of interest, large unwanted signals, or interferers, can also couple onto the antennas. This imposes stringent linearity requirements on the LNA. Furthermore, LNAs in multi-standard radios (e.g. software defined radios) need to meet the performance of the most demanding standard that is supported, which often increases power consumption. Thus, there is a need for a low noise amplifier that can be adjusted to the desired frequency of operation, noise figure and linearity so that the power consumption can be optimized. This technology is a field programmable low noise amplifier with interfere-reflecting loops for LNA input linearity enhancement.

Field programmable LNA with interferer reflecting loop boosts signal while decreasing noise

This technology uses frequency selective shunt-shunt feedback to lower the input impedance of the LNA outside the frequency band of interest while maintaining in-band input matching. The low input impedance reflects interferers by reducing their voltage swings. Specifically, the implementation of an interferer-reflecting loop and a notch filter allows this technology to overcome challenges of traditional low noise amplifiers by allowing out-of band-blockers to be rejected at the input of the low noise amplifier. The field-programmable low noise amplifier dynamically adjusts power consumption based on real time signal quality requirements of the desired wireless standard. Thus, this technology could potentially increase signal quality and strength as well as prolong battery life in wireless systems.

A prototype of the technology with a programmable gain ranging from 9 dB to 22 dB for a target frequency of 1 GHz has been characterized and used to demonstrate differences in variety of notch filters.

Lab Director:

Peter Kinget, Ph.D.


  • Signal amplifier for reconfigurable radio frequency systems whose signal quality requirements vary with different standards
  • Portable wireless devices, such as mobile phones or GPS, where optimizing power consumption is important for maximizing battery life
  • Reconfigurable radios, such as cognitive radios that can detect and adapt to different frequencies


  • In-field tradeoff between performance specifications (such as linearity, noise, and power consumption)
  • Highly programmable in terms of gain, noise figure (NF) and linearity
  • Rejection of out-of-band blockers at input of the low noise amplifier for reduction or elimination of the band selection filter

Patent Information:

Patent Pending (US 20160359459)

Tech Ventures Reference: IR CU14321