DC INSTABILITY OF THE SERIES CONNECTION OF TUNNELING DIODES

An oscillator with a series connection of tunneling diodes produces si gnificantly higher power than a single diode oscillator, However, a ci rcuit with series-connected tunneling diodes biased simultaneously in the negative differential resistance (NDR) region of the I-V curve is de unstable, This de instability makes the series connection oscillato r fundamentally different from a single diode oscillator. Associated w ith the de instability are the phenomena of minimum oscillation amplit ude and frequency, Due to the minimum oscillation amplitude, it is cri tical to provide the impedance match between the oscillator circuit an d the series connection at the desired oscillation amplitude level, An in depth, comprehensive analysis of the de instability is given here, Based on this analysis, a numerical procedure is developed to accurat ely predict the minimum oscillation amplitude and frequency, Time doma in simulations which give further insight into series-connection oscil lator behavior are discussed, The effect of increasing the number of d iodes on the oscillator performance is explored as well, Based on nume rical and simulation results, oscillators with several tunnel diodes c onnected in series were designed and tested, Experimental results that confirm the existence of the minimum oscillation amplitude are presen ted for oscillators with two, three, and four tunnel diodes.