Synthesis of frequency-independent phase shifters using negative group delay active circuit

Application of negative group delay active circuits to the design of broadband and constant phase shifters

The new phase-shifter configuration described in this report uses a negative group delay (NGD) active circuit. In this topology, a classical transmission line is set in cascade with an NGD circuit whose phase slopes are alike, but opposite, to get a constant and broadband phase shift. The proposed approach was validated through the design and measurement of a phase shifter, which exhibited a co...

Broadband Microwave Negative Group Delay Transmission Line Phase Shifters

W-Band True-Time Delay Phase Shifters Using Paraffin Microactuators

We report a distributed loaded line phase shifter based on a new class of electro-thermally actuated RF MEMS devices using paraffin phase-change material (PCM). Paraffin is a low loss (tan δ = 6.6×10−4) mechanical phase-change material that exhibits a 15% volumetric change through its solid-liquid transition. Due to its unique electrical and mechanical properties, paraffin PCM variable capacito...

Negative Group Delay and Superluminal Propagation: An Electronic Circuit Approach

We present a simple electronic circuit which provides negative group delays for band-limited, base-band pulses. It is shown that large time advancement comparable to the pulse width can be achieved with appropriate cascading of negative-delay circuits but eventually the out-of-band gain limits the number of cascading. The relations to superluminality and causality are also discussed.

A Miniaturized Self-Matched Negative Group Delay Microwave Circuit

A miniaturized self-matched negative group delay (NGD) microwave circuit without the need for external matching networks is proposed. The NGD circuit is based on a modified parallel-type RLC resonator, in which lumped elements (capacitors and inductors) are implemented by microstrip gaps and high-impedance and short-circuited microstrip lines. To verify the design concept, an NGD circuit with t...