Impact of small antenna on linear power amplifier performance in a co-design approach

The main objective of this study is to determine the impact of a co-designed small antenna on linear power amplifier (PA) performances. Special attention is paid to load-pull optimization to derive suitable values of the antenna input impedance at the operating frequency and the first higher-order harmonics. The impact of the antenna impedance profile in the operational band on PA performance is also addressed. It is found that the PA is more linear, when its operating frequency is below the antenna resonance, compared to other configurations. A microstrip patch antenna which provide the optimal impedance is developed and results demonstrate the benefits of the co-design approach with new antenna.