Series Resistance of Silicon Millimeter Wave (Ka-band) IMPATT Diodes

Abstract

The paper describe a computer-based method to calculate the series resistance R s of a millimeter wave Ka-band packaged IMPATT diode from small signal conductance-susceptance characteristics. The series resistance R s has been calculated at the threshold condition when the small signal conductance of the packaged diode just becomes negative and the device susceptance becomes positive. Again, the value of series resistance R s has been determined from the measurement of threshold current and threshold frequency with the silicon Ka-band IMPATT diode embedded in a resonant cap cavity which agrees well with the values obtained by the computer method.

A proposed simulation technique to study the series resistance and related millimeter-wave properties of Ka-band Si IMPATTs from the electric field snapshots

“…They determined the series resistance of the device used as a power source in an oscillator circuit by measuring the threshold current at resonant frequency. Some theoretical and experimental studies were later reported [7, 8] on the electrical series resistance of X- and Ka-band IMPATT diodes. The series resistance of millimeter-wave Ka-band IMPATTs was calculated from small-signal simulation [8] and the same was compared with the experimental data.…”

Effects of tunnelling current on millimetre-wave IMPATT devices

“…Due to the errors associated with network analyser and the difficulties associated with the accurate device-circuit modelling, the direct measurement of series resistance is almost impossible (Misawa, 1967;Ray & Gupta, 1988). Several authors have proposed different indirect procedures to measure the series resistance of IMPATT devices (Adlerstein, Holway, & Chu, 1983;Mitra, Das, Kar, & Roy, 1993;Pal, 2009). Out of those methods, the modified Adlerstein method of indirect measurement of series resistance of the device reported by Mitra et al (1993) is the most promising and accurate one.…”

“…Out of those methods, the modified Adlerstein method of indirect measurement of series resistance of the device reported by Mitra et al (1993) is the most promising and accurate one. Figure 3 shows an equivalent circuit for packaged IMPATT device (Adlerstein et al, 1983;Brooker, 2006;Pal, 2009). In Figure 3, G and B are the negative conductance and susceptance of the device, respectively.…”

“…The oscillation goes on to build up for a number of cycles until the magnitude of the negative conductance of the device decays to the value of positive conductance of the RF circuit and the oscillation finally becomes stable (Kurokawa, 1969). In the practical case, it is a valid approximation to assume g = 0 at the threshold of oscillation since |G th | >> g at that time (Adlerstein et al, 1983, Adlerstein & Moore, 1981Mitra et al, 1993;Pal, 2009). Thus, at the threshold condition, Equation (34) reduces to:…”

“…G th and B th ), A j and B pack , the value of the series resistance (R S ) can be calculated from Equation (30). Here the authors have used the oscillation threshold condition for estimating the value of R S (Adlerstein et al, 1983;Adlerstein & Moore, 1981;Mitra et al, 1993;Pal, 2009) and confirmed that though the parasitic series resistance (R S ) of the device is an inherent property of the device itself (it originates from the unswept epitaxial layers, substrate layer and contact layers of the International Journal of Electronics 1439 device as discussed earlier), its value can be estimated from the knowledge of G th and B th (at oscillation threshold). But in case of steady-state free running oscillator, the Kurokawa condition ( (Kurokawa, 1969) (i.e.…”