Inkjet-Printed Circuit Board Technology for User Terminal Antennas

Status date
The objective of this activity is to: demonstrate by design, manufacture, and test of antenna demonstrators that inkjet printing technology is a suitable alternative to build low-cost user terminal antennas. The prototype antennas consist of a printed circuit board for the radiating elements and associated passive beam forming network. The following specific objectives are included:
  • Identify potential user terminal applications that may benefit from the use of inkjet-printed circuit board (iPCB) technology;
  • Trade-off inkjet-printed circuit board technologies in terms of cost, performance, and environment friendliness;
  • Perform an extensive sample test campaign to assess the iPCB technology;
  • Demonstrate the applicability and RF performances of such technology by means of manufacturing and testing of two different user terminal antenna demonstrators, incorporating the radiating elements and passive beam forming network.
The key issues addressed in the current activity are the following:
  • Development of iPCB technology with sufficient RF performance and environmental robustness and acceptable process throughput.
  • Development of iPATCH antenna demonstrators with customisability and sufficient RF performance.

Compared to traditional PCB technology, the potential benefits of iPCB technology in antenna manufacturing include the following: (1) cost savings are possible, (2) environmental burden can be reduced, (3) new types of devices can be manufactured, and (4) personalization becomes easier. The antenna demonstrators of the current activity capitalise on the personalization feature of iPCB technology: to manufacture planar array antennas for fixed satellite services with individually tailored, fixed and directive antenna beam. Thus improved directivity (and link budget margin) can be generated for each individual installation location and orientation without costly electrical steering solutions of the antenna array. Compared to high gain parabolic antennas, the tailored planar array antennas enable flat panel design that can be mounted flat to a wall or a roof without protruding parts. Thus, the solution is both visually attractive and environmentally very robust.  

The developed iPCB technology is based on 5-7 um thick silver ink (ANP DGP 40LT-15C) layer printed on a cost-effective, low-loss Premix PREBOARD substrate (εr = 2.55, tanδ = 0.001). The measured DC conductivity of the conductors varied from sample to sample, but was up to 25% of that of bulk copper. Before printing, the substrate is subjected to O2 plasma activation and coated with Aerodisp W440 Al2O3 coating. The applied sintering temperature is 150 degC for 30 min. Finally, the printed substrate is treated with spray acrylic coating for mechanical and environmental protection.
To demonstrate the applicability of the iPCB technology, iPATCH antenna demonstrators have been designed, manufactured, and measured for two satellite applications: transmit and reception of voice, internet, and multimedia at L band and reception of satellite radio broadcasts at S band. The developed iPATCH antenna demonstrators are 2x2 antenna patch arrays; the L band antenna consists of two substrate layers while the S band antenna consists of a single substrate layer. The achieved G/T values for the L band antenna (receiving band) and S band antennas are -12.6 dB/K and -17.6…-18.1 dB/K, respectively (excluding beam pointing error) and the achieved antenna gain for the L band antenna (transmit band) is 11.5 dBi.
The activity has been divided into seven tasks as follows:
  • Task 1: Selection of the user terminal applications and the definition of inkjet-printed circuit board (iPCB) requirements for the associated antennas;
  • Task 2: Trade-off between various iPCB technologies;
  • Task 3: Definition and manufacturing of iPCB;
  • Task 4: iPCB sample test campaign to assess the compliance of the technology to the requirements of Task 1;
  • Task 5: Design and RF analysis of iPATCH antenna demonstrators
  • Task 6: Manufacturing and testing of iPATCH antenna demonstrators
  • Task 7: iPCB technology status update and iPCB technology evaluation plan.
Current status

The activity has been completed in December 2013.