Low noise amplifiers (LNAs) are an integral part of every high performance integrated circuit receiver. Current LNA approaches for high performance applications suffer from either nonlinear noise cancellation or dramatically high power consumption. This technology solves the primary limiting factor for linearity and noise in LNAs used in integrated applications. By implementing a passive (voltage) gain network using three magnetically coupled coils to achieve voltage gain and complete noise cancellation, this high performance device is limited only by the quality of the available passives and practical implementations. In particular, this technology addresses ultra-low voltage operation LNA circuits suitable for future nanoscale CMOS processes.

Use of passive elements to achieve voltage gain avoids the noise distortion and nonlinearity that arises from active amplifiers

The source-degenerated LNAs found in literature provide impressive noise figure numbers but suffer from degraded linearity from the passive gain in the input-matching network. At the same time, noise cancelling LNAs use an active gain mechanism to achieve linear noise performance at the cost of dramatically high power consumption. This technology relies on mutual inductances from three separate coils to perform noise cancellation, whereas current LNA designs use mutual inductance between only two coils, resulting in imperfect noise cancellation due to the impedance levels required.

The use of a fully passive gain system in this technology achieves linear gain while completely cancelling noise.

Lab Director:

Peter Kinget, Ph.D.

Applications:

Receivers for wireless data transmission (e.g. GPS, Bluetooth, ISM Radios, Wireless LAN, etc.)
Ultra-low voltage operation LNA circuits suitable for future nanoscale CMOS processes
Satellite Communications
Cellular Phones
Short range tracking device

Advantages:

Avoids the noise distortion and nonlinearity that arise from active amplifiers
Ultimately limited only by the quality of the available passives and practical implementations
Completely cancels the noise (and distortion) of the non-linear device in question
Voltage gain (rather than power gain) is achieved through a fully passive gain network

Patent information:

Patent Issued

Tech Ventures Reference: IR CU14031

Use of passive elements to achieve voltage gain avoids the noise distortion and nonlinearity that arises from active amplifiers

Lab Director:

Applications:

Advantages:

Patent information:

Related Publications:

Passive low noise amplifier achieves linear signal amplification and complete noise cancellation for high performance integrated circuit applications