High isolation single lambda antenna for dual communication systems

摘要

An antenna system includes an antenna element having two antenna feeds and a shared connection to a ground plane. A first antenna portion has a first resonant frequency length of at least one first wavelength formed from a first feed together with the shared ground connection. A second antenna portion has a second resonant frequency length formed from a second feed together with the shared ground connection. First and second slots are respectively positioned between the shared ground connection and the respective first and second feeds such that the slots create inductances. At least a portion of the ground plane is located directly beneath at least a portion of the first and second slots. The first and second slot inductances together with the ground plane capacitances form one or more filter components to isolate the first and second resonant frequencies in the antenna element.

主权项

1. An antenna system comprising:
an antenna element; a ground plane; and a substrate wherein the antenna element is a planar conductive material disposed on a first surface of the substrate and the ground plane is a planar conductive material disposed on a second surface of the substrate; the antenna element comprising: a first antenna element portion having a first radiating plane, a first resonant frequency and a first resonant frequency length, the first resonant frequency length being formed from a first antenna feed together with a shared ground connection coupled to the ground plane, the shared ground connection being conductively connected to the ground plane through the substrate, the first antenna feed being positioned in the first antenna element portion, wherein the first resonant frequency length is formed by resonance lengths of first segments making up the first antenna element portion, and wherein the first segments include the first radiating plane, the first antenna feed and the shared ground connection; a second antenna element portion having a second radiating plane, a second resonant frequency and a second resonant frequency length, the second resonant frequency length being formed from a second antenna feed together with the shared ground connection, the second antenna feed being positioned in the second antenna element portion, wherein the second resonant frequency length is formed by resonance lengths of second segments making up the second antenna element portion, said second segments including the second radiating plane, the second antenna feed and the shared ground connection; at least a first slot placed between the first antenna feed and the shared ground connection to create a first inductance; at least a second slot placed between the second antenna feed and the shared ground connection to create a second inductance; wherein: the first and the second antenna element portions form two independent radiating portions sharing one single ground plane; the ground plane only partially overlaps the first slot to create a first capacitance, and the second slot to create a second capacitance; the first inductance, the first capacitance, the second inductance and the second capacitance create an equivalent of an isolation band-stop filter for increasing the isolation between the first and second resonant frequencies in the first and second antenna element portions of the antenna element; and the ground plane has a size and a shape both selected based on sizes and shapes of the first slot and of the second slot so as to create a desired overall balance of impedance matching of each antenna element portion and isolation between the two antenna element portions.