Patent number: 10187107
Filed: Apr 23, 2018
Date of Patent: Jan 22, 2019
Assignee: Nokia Solutions and Networks Oy (Espoo)
Inventors: Senad Bulja (Dublin), Rose Kopf (Greenbrook, NJ)
Primary Examiner: Blane Jackson
Application Number: 15/959,564
In this invention a switch based on EC materials is presented, its structure is shown in Figs. 1 and 2. Fig. 1 shows one realisation of an RF switch using EC materials. It consists of a microstrip line mounted on a substrate formed using WO3 and NiO sandwiching a conductor, as shown in Fig.2. The microstrip line is connected to a DC bias using a high impedance (narrow line). The bias line extends over the EC substrate, the dielectric spacer and reaches the LiNbO3 substrate. Mounted on the LiNbO3 substrate is a conductive pad. In the absence of any dc bias voltage, the microstrip line behaves as a simple transmission line, however, its character changes upon the application of dc bias.
Two dc bias voltages are necessary for the operation of the microstrip line as a switch. Vdc1 is applied between the conductive pad and the ground plane in order to set the LiNbO3 ions in motion. Once in motions, these ions, by virtue of Vdc2 are moved towards the RF microstrip line, where they subsequently get injected into the chromic layers (WO3 and NiO). Upon intercalation the chromic layers become conductive, which short-circuits them with the middle conductor. Now, the microstrip line is entirely short circuited, which is needed for the correct operation of the switch.