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Clean Sky

Antenna Concept Evaluation and Improvement

The proposed antenna design seems very promising in terms of SWAP – C (“Size Weight and Power – Cost”) performances, due to the printed circuit technology selected.

Electrical performances seems promising too, nevertheless further activities of tuning and optimization of the design are necessary.

Material Selection

The material of the breadboard (ARLON AD300) was selected because is a good compromise between cost and properties suitable to demonstrate the feasibility of the antenna concept. Nevertheless the antenna substrate is the first item to improve.

ROGER RT Duroid 5880 could be an interesting upgrade of the project to reduce losses by combining two effects:

  1. very low tgloss (0.0009)
  2. thanks to the er=2.2, a new design of the series fed network can be arranged leading to a shorter circuit and consequently to lower losses

A reduction of 1dB is feasible with an expected final efficiency between 55% and 60%.

New design of series fed network

Combining a lower er material and a consequently new network design, the following items can be improved:

  1. Bandwidth, particularly referring to the radiated performances (SLL and HPBW) at the edge of coverage
  2. Losses reduction
  3. Lower error due to design uncertainties

Both simulated and measured data showed a degradation of the gain mask at the lower edge of the band, with larger beam and higher SLL than at band center as shown in the following figures:

Actual Series Fed Design

Actual Series Fed Design

New-possible Series Fed Design

New-possible Series Fed Design

Electrical Performance