Design of an Integrated cascode cell for compact Ku-band power amplifiers

Abstract

This paper reports on the design of a new power cell dedicated to Ku-band power amplifier (PA) applications. This cell called "'integrated cascode"' has been designed in order to propose a strong decrease in term of circuit size for Power Amplifier (PA). The technology used relies on 0.25-μm GaAs Pseudomorphic High Electron Mobility Transistors (PHEMT) of United Monolithic Semiconductors (UMS) foundry. A distributed approach is proposed in order to model this power cell. The challenge consists to obtain, with a better shape factor (ratio between the vertical and horizontal sizes of the transistor), the same performances than a single transistor with the same gate development. In order to design a 2W amplifier, we have used two 12x100 μm transistors. Cascode vertical size is 413 μm whereas a transistor with the same gate development exhibits a vertical size of 790 μm. Therefore the shape factor is nearly one as compared to a shape factor of 4 for a classical parallel architecture. This new device allows to decrease the MMIC amplifier area of 40 % compared with amplifier based on single transistors.

Design of X‐band power amplifier for leo satellite transmitter

“…Due to a high gain, cascode cell is sensitive to oscillations. That is why linear stability analysis must be performed . Figure shows the K ‐factor and the determinant delta of S matrix.…”

“…The interstage matching network has been designed to match the optimal load impedance of the driver stage to the conjugate‐complex source impedance of the following amplifier stage as shown in Figure (b). Passive elements such as capacitors are used for the realization of the matching network in the very same manner .…”

A 4W GaAs Power Amplifier MMIC for Ku-band Satellite Communication Applications

“…They are limited to produce very high output power, however they have some advantages such as outstanding high frequency characteristics and mature manufacturing process technology compared with GaNbased power amplifiers. In recent years, GaAs-based power amplifiers in Ku-band with 1 ~ 2W output power have been demonstrated [1][2][3][4][5][6].…”