Giorgio Polli

Resistive bias network for optimized isolation in SPDT switches

Classical Series-Shunt and T-shape SPDTs provide an isolation degrading in frequency which, to be adequately counteracted, may require high-value (and, therefore, large-size) resonating inductors. In this contribution, a resistive bias network is added to a T-shape SPDT instead of introducing inductors. A derived analytical description evidences that the maximum isolation can be shifted in frequency by selecting the proper resistive values. Such an architecture offers high isolation values and, at the same time, considerable area savings as compared to the inductor-based approach. A test circuit operating in S-Band was designed and a 72 dB isolation was achieved, as well as a return loss of about 20 dB.

High performance X-band LNAs using a 0.25 μm GaN technology

This work presents two LNAs, referred to in the following as LNA A and LNA B, respectively operating in the 8–10 GHz band and 10–12 GHz band; together they cover the full X-band. The power consumption results very low, being equal to 0.9 W for each amplifier. The total area for each LNA is 3.0×1.5 mm2. A very low noise figure has been achieved, namely of 1.1 dB (LNA A) and 1.3 dB (LNA B). The peak gain is 27 dB (LNA A) and 25 dB (LNA B). The obtained results mark an increase in performance for the 0.25 μm GaN technology in terms of noise figure, gain and matching, improving the current state of the art of GaN-based LNAs.

Q-band self-biased MMIC LNAs using a 70 nm InGaAs/AlGaAs process

In this paper, two self-biased LNAs are presented. Such amplifiers operate in the Q-band, covering 4 GHz between 42 GHz and 46 GHz. Both structu res are 2-stage configurations, adopting for each stage the common source topology with inductive feedback. The total area occupation for each LNA is 3.0×1.2 mm2. Noise figure lower than 1.55 dB has been obtained for version 1 and 1.5 dB for version 2. In-band gain for both versions is comprised between 17 dB and 19 dB, with a ripple lower than 0.5 dBpp/GHz.

High power-handling GaN switch for S-band applications

An asymmetrical switch architecture suitable for TRMs is proposed in this contribution. The design procedure and a test circuit are provided. The switch exhibits a 48.8 dBm input power-handling at a 0.1 dB power compression level and features an insertion loss less than 0.6 dB both in Rx- and Tx-mode.

An active dispersive delay line in GaN MMIC technology for X-band applications

This contribution provides a new design methodology to implement a dispersive delay line with active elements using a distributed structure. The concept of using CRLH and D-CRLH models in a distributed transversal filter is analyzed. A demonstrator using a filtering network as D-CRLH topology is proposed in order to obtain an active dispersive delay line in GaN technology. The MMIC operates in X-band and exhibits 0.6 ns of dispersion with piecewise linear trend between 8 and 12 GHz and a quite flat gain of about 22 dB.