A Universal Common-Source and Common-Drain Model for 1-20GHz Frequency Range

Abstract

element. It is not established if this approximation and the Extraction plays an important role in the performance of parameters extracted using the CS configuration are valid device models especiallyinthehighfrequencyr e.for other configurations such as CD. There is no work devle moelsespecially in the high frequency regime. The.. present day extraction techniques mostly use a groundedreported in literature which addresses whether the models source or common source (CS) device configuration. The extracted for grounded-source configurations are valid for models extracted from the grounded source devices are then non-grounded-source configurations. In circuits the used for devices in other configurations in a circuit devices are stacked, and are not necessarily in CS application. This leads to discrepancies in accurate prediction configuration and hence it is important to investigate the of the circuit performance. This work investigates, the models extracted using the CS configuration and study if applicability ofthe models extracted using CSfor other device they hold for other configurations. In this paper we present configurations. It was shown with the help of measured data, the need for enhancement in the present day models when in thefrequency range of 1-20 GHz, that the models extracted using transistors in configurations other than groundedfrom CS configuration do not predict the performance of a source configuration, in the frequency range of 1 to device in common drain (CD) configuration. Based on the 20GHz. The study of the gate impedance model that has to above observation, a universal gate impedance model that be included while using BSIM3 and BSIM4 models was works for both CS and CD confgurations for BSIM3v3 was carried out. developed. The gate impedance model was then extended to BSIM4 for both CS and CD configurations. The models for BSIM3v3 and BSIM4 are verified using simulations and II. CS ANDCD CONFIGURATIONSTEST compared with the measured data. STRUCTURESThe MOSFET is a four terminal device, but we I. INTRODUCTION normally make three terminal measurements, which would result in discrepancies of the extracted model. In order to One of the major drawbacks of RF circuit design is make sure that the components of the high frequency the lack of accurate models at high frequencies [1]. This is model are connected to the correct terminals, both CS and due to the fact that BSIM or any standardized model does CD structures were needed. A comparison of the not accurately model the device at high frequencies. The measured data from the CS and CD configurations was high-speed and RF applications require a sub-circuit carried out. model to predict the device operation accurately. Various components of the sub-circuit include gate resistance, Common source and common drain N-channel RFgate-source overlap capacitance, gate-drain overlap MOSFETS with different widths; lengths and number of capacitance, gate-bulk overlap capacitance, source series fingers (NF) were fabricated using LSI Logic's process resis...

On-chip Electromagnetic Interactions in CMOS Cascode LNAs

“…6 shows clearly that the magnitude and frequency discrepancies between simulations and measurements are seriously reduced by proper inclusion of EM analysis. The slight deviations in the absolute input matching values have its origin in lack of accurate input modeling of the NMOS transistor which also influences the noise performances [9], [16].…”