Motorola Corporation

Li Chen

Eric LeRoy Krenz

Thomas Anthony Petrella

Narendra Pulimi

Roger J Jellicoe

Richard Huang

Vimal Natarajan

Enrico J DiMario

Leslie Dean Mutz

A dual-band cellular telephone antenna. A monopole antenna is tuned to a first resonant frequency of operation. A first helical antenna is coupled to the monopole antenna and has turns surrounding the monopole antenna, where the first helical antenna is tuned to a second resonant frequency of operation. A grounded second helical antenna surrounds the first helical antenna and is formed to have an upper capacitive loading segment to tune the grounded second helical antenna at substantially the second resonant frequency of operation. The cellular telephone has a housing formed of a conductive material. A printed circuit board (PCB) has a metalized ground plane, wherein the metalized ground plane and the grounded second helical antenna are coupled to the cellular telephone housing.

Antenna apparatus with inner antenna and grounded outer helix antenna

A telescoping antenna ( ) has a mast element ( ) with first and second ends ( ), the first end ( ) being mounted on a cellular telephone housing ( ) and establishing electrical connection with signal processing circuitry ( ) within the cellular telephone ( ). The telescoping antenna ( ) also has a cylindrical radiating element ( ) that slidably engages the mast element ( ). In a retracted or stowed position first ends ( ) of the mast element ( ) and the cylindrical radiating element ( ) are substantially adjacent, and second ends ( ) of the mast element ( ) and the cylindrical radiating element ( ) are also substantially adjacent. A loading coil ( ) has a first end ( ) permanently connected to the second end ( ) of the cylindrical radiating element ( ) and has a second end ( ) engageable with the second end ( ) of the mast element ( ). The loading coil ( ) engages the mast element ( ) when the antenna ( ) is in a stowed position, and is disconnected from the mast element ( ) when the antenna ( ) is in the deployed position. The antenna ( ) provides a substantially constant frequency of operation in both an extended and retracted orientation.

Minimum frequency shift telescoping antenna

An antenna (116) includes an antenna cap (1300), a helical coil (1302), and a bushing (1304). The antenna cap (1300) is sized to fit the helical coil (1302) and forms a bushing threading. The bushing (1304) forms a cylindrical portion (1320) and a cylindrical portion (1322). The cylindrical portion (1320) is sized to receive the helical coil (1302). The cylindrical portion (1322) defines a cap threading and is configured to threadedly receive the antenna cap (1300).

Antenna assembly for a radiotelephone

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Buffalo Grove, IL, United States of America

Li Chen