Workplan › Work Package 4

WP4: Smart Q-band programmable multi-beam Antennas

Leader Participants
Fraunhofer TCF, ONERA, THALES

Objectives of this work package "Innovative Smart Antennas components for relays and terminals" are:

The best performing and cost effective antenna developed in this work package will be then used for platform integration (WP6) and field trials (WP7).

In particular, this WP covers the development of novel programmable multi-beam Q-band antennas with electronic beam forming and beam scanning capability. One will be a circular switched parasitic array (CSPA) antenna with large field of view for use in the link between the repeater and the subscribers. The concept is based on an array with passive antenna elements that can be controlled electronically. The work will also include the investigation of other beam scanning or switching antenna designs such as lens antennas in order to benefit from its high gain capabilities within a reduced field of view.

Multi-beam Lens Antenna

The idea behind the multi-beam lens antenna is to shape the beam generated by a lens antenna in order to distribute the energy in the required direction (i.e. where there is a terminal), as opposed to a sectorial antenna where a whole sector (typical 90°) is illuminated. For the SARABAND demonstrator a beam splitting with 3 sub‐beam, each with more than 20-dBi gain, has been implemented for the NTE links.

CSPA Antenna

In the second year of the project a first fixed-beam demonstrator of the circular switched parasitic array antenna, shown in Figure 1, was manufactured. This antenna had no electronic beam steering capabilities, yet.

Figure 1

Figure 1. Photograph of first fixed-beam demonstrator of the Q-band circular switched parasitic array antenna

During the third year of the project the CSPA antenna development has been successfully finalized and the switchable version is now available, as shown in Figure 2. The designed antenna has an impedance bandwidth of 3.45%, centered at 42 GHz, and the maximum measured gain is more than 10 dBi. Remote controlled switching of the beam direction is successfully demonstrated, covering the complete 360° field of view in the H-plane. The azimuth and elevation beamwidth are 6.5-7° and 80°, respectively.

CSPA antenna prototype

Figure 2. The switchable CSPA antenna prototype with the RF module and modem

Further investigations on the CSPA antenna have led to a novel design. Thanks to the use of a reflector the lateral dimensions, weight, and material costs are significantly reduced while the antenna gain is improved by approximately 5 dB, thus achieving a realized gain of more than 15 dBi.