# US 2019/0319344 A1 · Antenna tuning circuits, modules, and systems and related techniques > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0319344 A1 - Document ID: US20190319344A1 - Status: Published application - Kind: A1 - Application number: 16/454,504 - Filed: 2019-06-27 - Published: 2019-10-17 - Earliest claimed: 2017-01-17 - Inventors: Martin F. Jue - Web page: https://patentgrep.com/patent/US20190319344A1 ## CPC - H01Q 1/3208: {characterised by the application wherein the antenna is used} - H01Q 9/32: Vertical arrangement of element (H01Q9/40 takes precedence) - H01Q 1/24: with receiving set - H01Q 1/3283: {side-mounted antennas, e.g. bumper-mounted, door-mounted (mounted on windscreens H01Q1/1271)} - H01Q 1/38: formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142)} - H01Q 5/335: at the feed, e.g. for impedance matching - H01Q 9/30: with feed to end of elongated active element, e.g. unipole (H01Q9/44 takes precedence) - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract In accordance with some embodiments, an automatically tunable mobile antenna is provided with toroidal inductors connected in series between the antenna feed point and a whip and a shunt inductor to ground at the RF input, with the inductors forming an L network impedance matching circuit having values which are in a binary sequence and which are selectively added to impedance match the whip to the output impedance of a transmitter. In accordance with some embodiments, an automatically tunable mobile antenna is provided with a variable toroidal inductor assembly connected between the antenna feed point and the whip having a variable inductance based on selective shorting and un-shorting of wire windings to impedance match the whip to the output impedance of the transmitter. ## Claims ### Claim 1 An antenna tuning device configured to be connected between a radio frequency (RF) signal source and an antenna, the antenna tuning device comprising: a toroidal inductor comprising a plurality of windings of electrically conductive wire; a shaft extending through a center region of the toroidal inductor and configured to rotate within the center region of the toroidal inductor; and a movable contact arm connected to an end of the shaft, wherein by rotating the shaft within the center region of the toroidal inductor, the movable contact arm rotates so as to selectively electrically short at least one of the windings of wire contacted by the movable contact arm, thereby changing an inductance of the toroidal inductor. ### Claim 2 (depends on 1) The antenna tuning device of claim 1, wherein the toroidal inductor comprises an air core. ### Claim 3 (depends on 1) The antenna tuning device of claim 1, wherein the toroidal inductor comprises at least one of a powder-iron core, a ferrite core, and a brass core. ### Claim 4 (depends on 1) The antenna tuning device of claim 1, wherein the toroidal inductor is of generally circular or elliptical cross-sectional geometry. ### Claim 5 (depends on 1) The antenna tuning device of claim 1, wherein the toroidal inductor is of generally rectangular or square cross-sectional geometry. ### Claim 6 (depends on 1) The antenna tuning device of claim 1, wherein the electrically conductive wire comprises at least one of copper (Cu), aluminum (Al), and silver (Ag). ### Claim 7 (depends on 1) The antenna tuning device of claim 1, wherein the movable contact arm is configured to contact only a single winding of wire at a time. ### Claim 8 (depends on 1) The antenna tuning device of claim 1, wherein the movable contact arm is configured to contact a plurality of windings of wire at a time. ### Claim 9 (depends on 1) The antenna tuning device of claim 1, wherein the movable contact arm is an assembly of at least two bodies. ### Claim 10 (depends on 1) The antenna tuning device of claim 1, wherein the movable contact arm is of single-piece construction. ### Claim 11 (depends on 1) The antenna tuning device of claim 1, wherein the shaft is configured to be rotated manually. ### Claim 12 (depends on 1) The antenna tuning device of claim 1, wherein the shaft is configured to be rotated mechanically. ### Claim 13 (depends on 1) The antenna tuning device of claim 1, wherein the shaft is configured to be rotated both manually and mechanically. ### Claim 14 (depends on 1) The antenna tuning device of claim 1, further comprising a motor connected to the shaft and configured to rotate the shaft within the center region of the toroidal inductor. ### Claim 15 (depends on 14) The antenna tuning device of claim 14, wherein the motor comprises at least one of a stepper motor, a DC motor, a gear-reduced motor with a position feedback potentiometer, and a servo motor. ### Claim 16 (depends on 14) The antenna tuning device of claim 14, further comprising a power supply configured to provide power to the motor in rotating the shaft. ### Claim 17 (depends on 14) The antenna tuning device of claim 14, further comprising a controller configured to control the motor in rotating the shaft. ### Claim 18 (depends on 1) The antenna tuning device of claim 1, wherein the RF signal source is a transmitter. ### Claim 19 (depends on 1) The antenna tuning device of claim 1, wherein the antenna is a whip antenna. ### Claim 20 (depends on 1) An antenna tuning module comprising: the antenna tuning device of claim 1; and a housing configured to at least partially house the antenna tuning device.