%0 Journal Article
%T Noise Performance of Heterojunction DDR MITATT Devices Based on at W-Band
%A Suranjana Banerjee
%A Aritra Acharyya
%A J. P. Banerjee
%J Active and Passive Electronic Components
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/720191
%X Noise performance of different structures of anisotype heterojunction double-drift region (DDR) mixed tunneling and avalanche transit time (MITATT) devices has been studied. The devices are designed for operation at millimeter-wave W-band frequencies. A simulation model has been developed to study the noise spectral density and noise measure of the device. Two different mole fractions and of Ge and corresponding four types of device structure are considered for the simulation. The results show that the -Si heterojunction DDR structure of MITATT device excels all other structures as regards noise spectral density ( £¿sec) and noise measure (33.09£¿dB) as well as millimeter-wave properties such as DC-to-RF conversion efficiency (20.15%) and CW power output (773.29£¿mW). 1. Introduction Impact avalanche transit time (IMPATT) devices are noisy devices having an average noise level of 30¨C40£¿dB [1¨C4]. The noise in IMPATT devices arises mainly from random nature of carrier generation by impact ionization and avalanche multiplication phenomena. The intrinsic avalanche noise in IMPATT device depends mainly on the carrier ionization rates in the base semiconductor material [5]. The group IV-IV compound semiconductor, has been used as an important base material for both optoelectronic and microelectronic devices [6¨C9]. is a bandgap engineered material whose material properties depend on the Ge mole fraction ( ) [10]. Mixed tunneling avalanche transit time (MITATT) device is an important member of avalanche transit time (ATT) device family operating at higher millimeter-wave frequencies [11¨C23]. In 1958 W. T. Read [11] in his very early paper predicted that band-to-band tunneling phenomenon might limit the DC-to-RF conversion efficiency of the IMPATT diodes at high frequencies. Kwok and Haddad [12] reported the effect of tunneling on the negative conductance of the device. They considered that instantaneous carrier generation process through tunneling is equivalent to that of a field-dependent carrier source. This concept gave birth to new modes of IMPATT device, namely, MITATT and tunnel transit time (TUNNETT) modes. Nishizawa et al. [13] described the design and principle of the pulse oscillation characteristics of GaAs TUNNETT diodes. Elta and Haddad [14, 15] analyzed the high frequency performance of IMPATT diode by using a modified Read-type equation and considering dead space correction for impact ionization for the charge carriers. They proposed that the above mentioned three different modes (pure IMPATT, MITATT, and TUNNETT modes) of operation of IMPATT depend
%U http://www.hindawi.com/journals/apec/2013/720191/