Tunable Antenna With Slot-Based Parasitic Element

• US 20140266922A1
• Filed: 03/18/2013
• Published: 09/18/2014
• Est. Priority Date: 03/18/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Jin, Nanbo, Ouyang, Yuehui, Zhou, Yijun, Ayala Vazquez, Enrique, Schlub, Robert W., Pascolini, Mattia, Mow, Matthew A., Lakshmanan, Anand
• Granted Patent: US 9,331,397 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/24 with receiving set
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/10 Resonant antennas
• CPC Class Codes: H01Q 5/15 for operation of centre-fed antennas comprising one or more collinear, substantially straight or elongated active elements
• CPC Class Codes: H01Q 5/314 using frequency dependent circuits or components, e.g. trap circuits or capacitors
• CPC Class Codes: H01Q 9/06 Details

Abstract

Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form a dual arm inverted-F antenna. The antenna may have a resonating element formed from portions of a peripheral conductive electronic device housing member and may have an antenna ground that is separated from the antenna resonating element by a gap. A short circuit path may bridge the gap. An antenna feed may be coupled across the gap in parallel with the short circuit path. Low band tuning may be provided using an adjustable inductor that bridges the gap. The antenna may have a slot-based parasitic antenna resonating element with a slot formed between portions of the peripheral conductive electronic device housing member and the antenna ground. An adjustable capacitor may bridge the slot to provide high band tuning.

Claims

1. An electronic device antenna, comprising:

an antenna ground;

an antenna resonating element has a resonating element arm that is separated from the antenna ground by a gap; and

a slot-based parasitic antenna resonating element.

2. The electronic device antenna defined in claim 1 further comprising an antenna feed having positive and ground antenna feed terminals, wherein the slot-based parasitic antenna resonating element is not directly feed by the antenna feed and wherein the antenna resonating element has an additional resonating element arm.

3. The electronic device antenna defined in claim 1 wherein the antenna resonating element comprises a metal electronic device housing structure.

4. The electronic device antenna defined in claim 3 wherein the slot-based parasitic antenna resonating element comprises a slot having a portion that is interposed between the metal electronic device housing structure and the antenna ground.

5. The electronic device antenna defined in claim 4 wherein a first edge of the portion of the slot runs along the metal electronic device housing structures and wherein an opposing second edge of the portion of the slot runs along the antenna ground, the electronic device antenna further comprising a capacitor that bridges the slot.

6. The electronic device antenna defined in claim 5 wherein the capacitor comprises an adjustable capacitor.

7. The electronic device antenna defined in claim 6 wherein the capacitor comprises switching circuitry and multiple fixed capacitors coupled to the switching circuitry.

8. The electronic device antenna defined in claim 7 further comprising an adjustable inductor that bridges the gap.

9. The electronic device antenna defined in claim 8 wherein the adjustable inductor is adjusted to tune a first antenna resonance at a first frequency and wherein the adjustable capacitor is adjusted to tune a second antenna resonance at a second frequency that is greater than the first frequency.

10. The electronic device antenna defined in claim 9 further comprising a short circuit path coupled between the resonating element arm and the antenna ground across the gap.

11. The electronic device defined in claim 1 further comprising an adjustable inductor and an adjustable capacitor.

12. The electronic device defined in claim 1 further comprising an adjustable inductor coupled between the resonating element arm and the antenna ground across the gap.

13. The electronic device defined in claim 12 further comprising a short circuit path coupled between the resonating element arm and the antenna ground across the gap.

14. The electronic device defined in claim 13 further comprising an antenna feed coupled between the resonating element arm and the antenna ground in parallel with the short circuit path.

15. An antenna, comprising:

an antenna ground;

an inverted-F antenna resonating element that is separated from the antenna ground by a gap; and

a slot-based parasitic antenna resonating element.

16. The antenna defined in claim 15 wherein the slot-based parasitic antenna resonating element has a slot, the antenna further comprising a capacitor that bridges the slot.

17. The antenna defined in claim 16 wherein the capacitor comprises an adjustable capacitor.

18. The antenna defined in claim 17 further comprising an adjustable inductor coupled across the gap between the inverted-F antenna resonating element and the antenna ground.

19. The antenna defined in claim 18 wherein the inverted-F antenna resonating element comprises a dual arm inverted-F antenna resonating element formed from a portion of a peripheral conductive electronic device housing structure.

20. An antenna, comprising:

a dual arm inverted-F antenna resonating element formed from a metal electronic device housing structure;

an antenna ground that is separated from the dual arm inverted-F antenna resonating element by a gap;

a short circuit branch coupled between the dual arm inverted-F antenna resonating element and the antenna ground across the gap;

an antenna feed coupled between the dual arm inverted-F antenna resonating element and the antenna ground across the gap; and

a slot-based parasitic antenna resonating element having a slot.

21. The antenna defined in claim 20 further comprising an adjustable capacitor that bridges the slot.

22. The antenna defined in claim 21 wherein the slot has a portion with a first edge that is formed from the antenna ground and a second edge that is formed from the metal electronic device housing structure.

23. The antenna defined in claim 22 further comprising an adjustable inductor that bridges the gap.