Inkjet-printed array antenna

As part of the “Inkjet-Printed Circuit Board Technology for User Terminal Antennas” R&D project, Harp Technologies designed a dual band L-band antenna for receiving and transmitting satellite data (voice, Internet, and multimedia data). The project was funded by the European Space Agency (ESA) and the project partners were the VTT Technical Research Centre of Finland and Premix Ltd. The antenna was realised by VTT using inkjet printing, which is a novel manufacturing technology for Printed Circuit Boards (PCBs) with great future potential. The benefits include, for example, easy design customisation for each customer.

The operational frequency bands of the antenna are 1.542 GHz and 1.664 GHz for downlink and uplink, respectively, with a bandwidth of 34 MHz for both. The antenna as designed consists of two substrate layers separated by an air gap and the size is 24 cm x 24 cm x 1.7 cm. The overall design requirements that were set were achieved and the measured total power patterns match very well with the simulated ones in terms of pattern shape, maximum gain, and sidelobe level. The measured maximum gains of 12.0 dBi (uplink) and 11.6 dBi (downlink) deviate only minimally from the simulated ones, which were 12.1 dBi and 11.8 dBi, respectively. The simulations were performed using the CST MICROWAVE STUDIO® software.

The dual-band array antenna
The dual-band array antenna that was developed for receiving and transmitting satellite data (voice, Internet, and multimedia data) in the L-band. The antenna was realised using inkjet printing, which has great future potential in comparison with the conventional PCB photolithography technique.
Simulated surface currents on an aircraft
The antenna that was developed shows a very good match between the simulated (dashed line) and measured (continuous line) total power antenna patterns observed for both the downlink (left) and uplink (right) frequency bands.

 

Ground station

Harp Technologies Ltd has performed a study for the Finnish Meteorological Institute, Arctic Research Centre (FMI-ARC) to establish the requirements for a new satellite ground station in Sodankylä in Finnish Lapland. The aim of this receiving station is to receive remote sensing satellite data from selected satellites. The work included, for example, the definition of the technical requirements of the ground station, the identification and evaluation of potential alternative station models produced by commercial suppliers, the generation of cost estimates, and the evaluation of the receiving station’s integration into the other systems of FMI-ARC. The most important technical requirement (figure of merit) was the G/T (gain over noise temperature), which was determined. In order to define the G/T requirement, it was necessary to accurately define the link budget for the satellites of interest. The G/T is strongly dependent on the size of the receiving antenna, which in turn has a major impact on the cost. Thus, the specification of the receiving station’s technical requirements was an optimisation task to minimise the cost for a given quality and statistical availability of the satellite data.

The results of Harp Technologies’ work were used by FMI-ARC for evaluation, planning, and budgeting purposes. After the funding decision, Harp Technologies supported FMI-ARC in its preparation of detailed technical requirements specifications for the Request for Quotation and finally, assisted in the evaluation of the technical proposals of the potential suppliers. After construction, FMI-ARC commissioned the defined X-band high-capacity satellite receiving station in Sodankylä in 2011.

The dual-band array antenna
FMI-ARC’s X-band high-capacity satellite receiving station in Sodankylä. The diameter of the antenna is 7.3 m. Harp Technology supported FMI-ARC in the definition, specification, and purchase phases.