SWITCHABLE DIVERSITY ANTENNA APPARATUS AND METHODS

• US 20130162486A1
• Filed: 12/21/2011
• Published: 06/27/2013
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Pulse Finland Oy (Yageo Corporation)
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Korva, Heikki, Raappana, Ari, Annamaa, Petteri
• Granted Patent: US 9,484,619 B2
• Time in Patent Office: Days
• US Class Current: 343/725
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• 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 5/378 Combination of fed elements with parasitic elements

Abstract

An active diversity antenna apparatus and methods of tuning and utilizing the same. In one embodiment, the active diversity antenna is used within a handheld mobile device (e.g., cellular telephone or smartphone), and enables device operation in several low frequency bands (LBs). The exemplary implementation of the active LB diversity antenna comprises a directly fed radiator portion and a grounded (coupled fed) radiator portion. The directly fed portion is fed via a feed element connected to an antenna feed. The coupled fed portion of the LB antenna is grounded, forming a resonating part of the low frequency band. A gap between the two antenna portions is used to adjust antenna Q-value. Resonant frequency tuning is achieved by changing the length of the grounded element. The LB feed element is disposed proximate the feed element of a high band diversity antenna, thus reducing transmission losses and improving diplexer operation.

Claims

1. Diversity antenna apparatus, comprising:

a first antenna apparatus configured to operate in a first frequency range and comprising a first feed portion configured to be coupled to a feed structure of a radio device; and

a second antenna apparatus configured to operate in a second frequency range, and comprising;

a first radiator comprising a second feed portion configured to couple a radiating portion to said feed structure;

a second radiator comprising a first portion and a second portion, the second portion configured to be coupled to a ground plane of the radio device; and

selector apparatus configured to selectively couple said first portion to said ground plane;

wherein said selector apparatus is configured to enable wireless communication of the radio device in at least two operational bands within said second frequency range.

2. The apparatus of claim 1, wherein the at least two operational bands comprise bands specified by a Long Term Evolution (LTE) wireless communications standard.

3. The apparatus of claim 1, wherein said second frequency range is lower in frequency than said first frequency range.

4. The apparatus of claim 1, wherein first feed portion configured to be coupled to the feed structure forms at least a portion of a coupled-feed configuration, the coupled feed configuration enabling the diversity antenna apparatus to be substantially insensitive to dielectric loading during device operation.

5. The apparatus of claim 4, wherein said first and second frequency ranges do not appreciably overlap in frequency.

6. The apparatus of claim 1, wherein the selector apparatus comprises a switch.

7. The apparatus of claim 6, wherein the switch comprises a single pole, multi-throw switch.

8. A mobile communications device, comprising:

an enclosure comprising a plurality of sides;

an electronics assembly comprising a ground plane and at least one feed structure;

a main antenna assembly configured to operate in a lower frequency range and an upper frequency range and disposed proximate a bottom side of said plurality of sides; and

a diversity antenna assembly disposed along a lateral side of said plurality of sides, said lateral side being substantially perpendicular to said bottom side.

9. The mobile communication device of claim 8, wherein the diversity antenna assembly comprises:

a first diversity antenna apparatus configured to operate in the upper frequency range and comprising a first feed portion coupled to said feed structure; and

a second diversity antenna apparatus configured to operate in the lower frequency range, and comprising;

a first radiator comprising a second feed portion configured to couple a radiating portion to said feed structure;

a second radiator, comprising a ground structure coupled to the ground plane; and

a selector element configured to selectively couple a selector structure of said second radiator to said ground plane; and

wherein said selector element is configured to enable wireless communication of the mobile communication device in at least four operational bands within said lower frequency range.

10. The mobile communications device of claim 9, wherein:

said ground structure is disposed proximate a first end of the second diversity antenna apparatus; and

said second feed portion is disposed proximate a second end of the second diversity antenna apparatus, said second end disposed opposite from said first end.

11. The mobile communications device of claim 10, wherein said selector structure is disposed in-between said second feed portion and said ground structure.

12. The mobile communications device of claim 10, wherein said second feed portion is disposed proximate said first feed portion.

13. The mobile communications device of claim 10, wherein:

said second feed portion and said first feed portion are each coupled to a feed port via a feed cable; and

proximity of said second feed portion to said first feed portion is configured to reduce transmission losses in said feed cable.

14. The mobile communications device of claim 13, wherein, said feed cable comprises a microstrip conductor.

15. The mobile communications device of claim 13, wherein, said feed cable comprises a coaxial cable.

16. The mobile communications device of claim 9, wherein, said selector element comprises a switching apparatus characterized by a plurality of states and configured to selectively couple said selector structure to said ground plane via at least four distinct circuit paths.

17. The mobile communications device of claim 16, wherein at least one of said distinct circuit paths comprises a reactive circuit.

18. The mobile communications device of claim 9, wherein a first distance between the first feed portion and the second feed portion is less than a second distance between the second feed portion and said selector structure.

19. The mobile communications device of claim 9, wherein:

the second diversity antenna is characterized by a longitudinal dimension and a transverse dimension, the longitudinal dimension being greater than the transverse dimension;

the second radiator is configured substantially parallel to the longitudinal dimension;

the main antenna is disposed in an area characterized by a shorter dimension and a longer dimension; and

the longitudinal dimension is configured substantially perpendicular to the longer dimension.

20. The mobile communications device of claim 19, wherein:

the area comprises a rectangle;

the transverse dimensions is substantially perpendicular to the longitudinal dimension; and

the shorter dimension is substantially perpendicular to the longer dimension.

21. The mobile communications device of claim 9, wherein said second diversity antenna is characterized by a cross-section having a first dimension of no more than 2.8 mm.

22. Active low band diversity antenna apparatus, comprising:

at least first and second radiating elements; and

a coupled feed configuration;

wherein the coupled feed configuration enables the diversity antenna apparatus to be substantially insensitive to dielectric loading during device operation; and

wherein said antenna apparatus configured to operate over several spaced bands of a lower frequency range required by a wireless communication network standard.

23. The apparatus of claim 22, wherein the standard comprises a Long Term Evolution (LTE) standard, and the several spaced bands are selected from the B17, B20, B5, B8, and B13 bands thereof.

24. The apparatus of claim 23, further comprising switching apparatus in operative communication with said at least first and second radiating elements and configured to alter resonant frequency of the antenna apparatus.

25. A low frequency range diversity antenna comprising:

a coupling element;

a first radiating element being adapted for direct coupling to a feed structure of a portable device via the coupling element; and

a second radiating element being adapted for connection to a ground plane via at least one ground point;

wherein the diversity antenna is fed via the coupling element.

26. The antenna of claim 25, wherein the coupling element is disposed at approximately a center of an edge of the ground plane.

27. The antenna of claim 25, wherein a resonating portion of the low frequency range diversity antenna is formed by grounding a part of the antenna.