Distributed Control System for Beam Steering Applications
A technique is described where the switch and/or tunable control circuit for use with an active multi-mode antenna is positioned remote from the antenna structure itself for integration into host communication systems. Electrical delay and impedance characteristics are compensated for in the design and configuration of transmission lines or parasitic elements as the active multi-mode antenna structure is positioned in optimal locations such that significant electrical delay is introduced between the RF front-end circuit and multi-mode antenna. This technique can be implemented in designs where it is convenient to locate switches in a front-end module (FEM) and the FEM is located in vicinity to the transceiver.
1 . An antenna system, comprising:
an multi-mode antenna comprising a radiating element and at least one parasitic element positioned proximate to the radiating element;
an active tuning circuit integrated with a front-end module, the front-end module comprising:
a switch configured to control a radiation mode of a plurality of radiation modes of the multi-mode antenna; and
a transmit/receive (T/R) switch configured to couple the multi-mode antenna to a power amplifier (PA) and a low noise amplifier (LNA).
2 . The antenna system of claim 1 , wherein the front-end module further comprises a duplexer coupled between the T/R switch and the PA and the LNA.
3 . The antenna system of claim 1 , wherein the front-end module is associated with a communication system.
4 . The antenna system of claim 1 , wherein the active tuning circuit configured to vary a reactance associated with the at least one parasitic element.
5 . The antenna system of claim 1 , further comprising a high-impedance transmission line coupling the switch of the front-end module to the at least one parasitic element.
6 . The antenna system of claim 5 , wherein the high-impedance transmission line comprises a single conductive trace.
7 . The antenna system of claim 5 , wherein the high-impedance transmission line comprises a coaxial transmission line, a microstrip transmission line, a stripline transmission line, a co-planar waveguide, or a parallel wire transmission line.
8 . The antenna system of claim 1 , further comprising:
a transceiver coupled to the front-end module;
a baseband processor coupled to the transceiver;
a control line coupling the switch and the T/R switch of the front-end module; and
an algorithm stored in a microprocessor of the front-end module,
wherein the algorithm is configured to control the multi-mode antenna.
9 . The antenna system of claim 1 , wherein the active tuning circuit is configured to configure the multi-mode antenna in one of the plurality of modes.
10 . The antenna system of claim 1 , wherein the multi-mode antenna is configurable in a plurality of modes, each of the plurality of modes having a distinct radiation pattern.
11 . The antenna system of claim 1 , wherein the at least one radiating element comprises:
a vertical portion disposed on the ground plane; and
a horizontal portion extending from the vertical portion.
12 . An antenna system, comprising:
a multi-mode antenna comprising a radiating element and at least one parasitic element positioned proximate to the radiating element;
an active tuning circuit integrated with a front-end module, the front-end module comprising:
a switch configured to shift the multi-mode antenna between a plurality of radiation modes;
a transmit/receive (T/R) switch couples to a duplexer; and
the duplexer configured to a power amplifier (PA) and a low noise amplifier (LNA).
13 . The antenna system of claim 12 , further comprising a high-impedance transmission line coupling the switch of the front-end module to the at least one parasitic element.
14 . The antenna system of claim 12 , wherein the active tuning circuit configured to vary a reactance associated with the at least one parasitic element.
15 . The antenna system of claim 13 , wherein the high-impedance transmission line comprises a coaxial transmission line, a microstrip transmission line, a stripline transmission line, a co-planar waveguide, or a parallel wire transmission line.
16 . The antenna system of claim 13 , wherein the active tuning circuit is configured to configure the multi-mode antenna in one of the plurality of modes.
17 . The antenna system of claim 13 , wherein the multi-mode antenna is configurable in a plurality of modes, each of the plurality of modes having a distinct radiation pattern.