Table 1 The simulation results of the designed WPDs at 0.5, 1, 1.5 and 2 GHz with equal power divisions at the output ports (NB: L_min = the lowest level of suppression).

Size reduction

96.64%

91.85%

82.2%

62.9%

Harmonics suppressed

2nd–100th

L_min = − 11.620 dB

2nd–50th

L_min = − 10.830 dB

2nd–34th

L_min = − 11.014 dB

2nd–25th

L_min = − 10.02 dB

S₁₁

− 26.923 dB

− 41.142 dB

− 27.925 dB

− 35.461 dB

S₂₁

− 3.019 dB

− 3.012 dB

− 3.021 dB

− 3.015 dB

S₂₂

− 45.038 dB

− 32.511 dB

− 60.694 dB

− 26.993 dB

S₂₃

− 23.468 dB

− 28.146 dB

− 24.772 dB

− 22.122 dB