Antenna apparatus and method of forming same

• US 20060250319A1
• Filed: 05/06/2005
• Published: 11/09/2006
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Koh, Boon Ping, Contreras, Nereydo T., Ooi, Sooliam L., Kontogeorgakis, Christos
• Granted Patent: US 7,202,836 B2
• Time in Patent Office: Days
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements

Abstract

An antenna provides dual band capability by providing a single feed (102) leading into a helix (104), the helix characterized by a pitch (106) and number of turns (120) varied to provide dual band operation to a portable communication device.

Claims

1. (canceled)

2. (canceled)

3. An antenna, comprising:

a helix formed of first, second and third sections;

a feed coupled to the first section;

the helical sections wound to provide a GPS frequency band of operation by utilizing an electrical wavelength of 0.25λ

for the first section, 0.25λ

for the second section and 0.75λ

for the third section, which makes up a total of 1.25λ

for the entire helix;

the second section providing an abrupt change in helix pitch that provides a discontinuity to generate a standing wave at the GPS frequency band; and

the helix dimensioned such that the first, second and third sections also provide a UHF frequency band of operation by utilizing a total electrical wavelength of 0.25λ

for the entire helix.

4-15. -15. (canceled)

16. A method for forming an antenna for dual band operation, comprising the steps of:

providing a helical radiating element having a single feed;

configuring a first section of the element to be a quarter wavelength at a GPS frequency band of the dual band of operation;

assigning a number of turns with abrupt difference in pitch for a second section of the element for charge accumulation and discontinuity in physical dimension;

selecting a number of turns and pitch combination for a third section to produce a total electrical length for the entire helix to be 1.25λ

; and

re-iterating the choice of pitch for the bottom section to optimize an impedance match for both UHF and GPS bands.

17. The method of claim 16, wherein the step of selecting the number of turns further includes the step of determining the wavelength per turn and calculating a resultant electrical length for the pitch.