the devices having only two electrodes and exhibiting negative resistance (the devices being tunnel diodes H03K17/58)

Full Title

Electronic switching or gating, i.e. not by contact-making and –breaking (gated amplifiers H03F3/72; switching arrangements for exchange systems using static devices H04Q3/52) > characterised by the components used (H03K17/04 - H03K17/30, H03K17/94 take precedence) > by the use, as active elements, of semiconductor devices (using diodes H03K17/74) > the devices having only two electrodes and exhibiting negative resistance (the devices being tunnel diodes H03K17/58)