Level shifter circuits are necessary parts of modern SoCs, as they interface different voltage domain signals. This paper presents an energy-efficient level up shifter capable of converting sub-threshold input signal to higher levels. The proposed design uses the feedback mechanism of a regulated gate cascode to achieve energy efficient operation. Once the desired output level is achieved, large static current does not flow, and static power is further minimized using a transistor stack. Implementing in a 90-nm process, post-layout simulation results show that the proposed level shifter has a propagation delay of 21.2 ns, a total energy-per-transition of only 77.5 fJ, and a static power dissipation of 7.2 nW.
In this paper, a compact triple-band bandpass filter (BPF) is proposed based on a triple-mode stub-loaded step-impedance resonator (SIR). The proposed SIR is formed by attaching two identical open stubs at the symmetrical sides of a step-impedance microstrip line, which can be explained using the even-odd-mode analysis method. A pseudo interdigital structure is used to realize the compact size of the filter, and two coupling paths are utilized. The three desired passbands can be conveniently allocated by properly choosing the dimension parameters of the stub-loaded SIR. The measured center frequencies of the three operation passbands are 2.2 GHz, 3.5 GHz and 4.6 GHz with a low insertion loss of 1.14 dB, 1.21 dB and 2.20 dB, respectively. Good agreement between the simulated and the measured results is observed.
This paper presented the development of a novel large-signal equivalent circuit model for InP-based pseudomorphic high electron mobility transistor (PHEMT) MMIC applications beyond 100 GHz. A new set of I-V functions was built in the large-signal model to depict accurately the measured I-V results of this device. The convergence of the model was good during the HB (harmonic balance) simulation. To verify the feasibility of the large-signal model, a 110 GHz MMIC amplifier based on this large-signal model was designed and fabricated, the on-wafer measured large-signal results, which include Pout, Gain and PAE (Power Add Efficiency), were consistent with the simulated ones at 110 GHz. Thus, this new large-signal model has a great potential for InP MMIC applications beyond 100 GHz.