A negative group delay (NGD) circuit with simple structure has been proposed by using an open-circuited resonator and a pair of short-circuited coupled lines which are connected with two shunt resistors. The centre frequency of the NGD circuit is dominantly controlled by the open-circuited resonator, while the shunt resistors connected coupled lines are utilised for port matching, which greatly attenuates S ₁₁ of the circuit. The proposed NGD circuit has been fabricated and measured, and the experiment shows an NGD time of − 4.6 ns, an NGD bandwidth of 120 MHz, and an S ₁₁ attenuation of >33 dB. The experimental results approach to the prediction.

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Matched NGD circuit with resistor-connected coupled lines

References

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