Small digital tunable antenna systems for wireless applications
View Patent ↗The instant disclosure provides an antenna system with a generically small ground plane and a generic antenna radiating module, wherein the system further includes a matching circuit and a tunable capacitor each bring integrated with the ground plane and antenna in a novel configuration which provides improved antenna performance across multiple antenna resonances.
1. An antenna system, comprising:
a substrate extending about a longitudinal axis to define a length thereof, and having a width, wherein on a top surface of the substrate is disposed each of:
a ground plane conductor, and
an antenna module;
the antenna module being disposed adjacent to the ground plane conductor and spaced apart therefrom to form a longitudinal gap therebetween;
the ground plane conductor comprising a channel extending inwardly from a side adjacent to the antenna module;
a feed conductor extending longitudinally about the top surface of the substrate from the antenna module to a terminus of the channel, the feed conductor being isolated from the ground plane conductor via a channel gap surrounding the feed conductor;
a ground connection element traversing the longitudinal gap from the ground plane conductor to a ground connection of the antenna module, wherein antenna module is configured to couple with the ground plane conductor via the ground connection element;
a matching circuit coupled to each of said feed conductor and said ground plane conductor; and
a tunable capacitor coupled to each of said feed conductor and said ground plane conductor.
2. The antenna system of claim 1 , said ground plane conductor comprising a pair of longitudinal ground conductors separated by said channel, wherein said longitudinal ground conductors and said feed conductor collectively form a coplanar waveguide.
3. The antenna system of claim 1 , wherein said tunable capacitor is disposed between said matching circuit and said antenna module.
4. The antenna system of claim 1 , wherein said matching circuit comprises one or more lumped components in series.
5. The antenna system of claim 1 , wherein said matching circuit comprises one or more lumped components in shunt.
6. The antenna system of claim 1 , comprising a bifurcated transmission line, said bifurcated transmission line comprising:
with said feed conductor having a first end and a second end each disposed about a longitudinal section of the feed conductor captured within the channel, the feed conductor being bifurcated at the first end to form a first feed segment and a second feed segment, and said first and second feed segments being combined at the second end;
a longitudinal ground strip disposed longitudinally between said first and second feed segments;
a first radiofrequency (RF) switch disposed at the first end of the feed conductor,
a second RF switch disposed at the second end of the feed conductor,
wherein each of the tunable capacitor and the matching circuit are coupled to the first feed segment between the first and second RF switches;
wherein said second feed segment is configured as a switchable bypass.
7. The antenna system of claim 6 , wherein a first of said longitudinal ground conductors, said first feed segment, and said longitudinal ground strip collectively form a first coplanar waveguide disposed between said first and second RF switches.
8. The antenna system of claim 7 , wherein a second of said longitudinal ground conductors, said second feed segment, and said longitudinal ground strip collectively form a second coplanar waveguide disposed between said first and second RF switches.
9. The antenna system of claim 6 comprising a pair of coplanar waveguides disposed between said first and second RF switches.
10. The antenna system of claim 1 , wherein said tunable capacitor comprises a digital tunable capacitor.
11. The antenna system of claim 1 , wherein said antenna module comprises a three-dimensional rectangular substrate with one or more conductor elements disposed on at least one side thereof.