A modified Wilkinson Power Divider is proposed in this paper that utilizes defected ground structure (DGS) in parallel with an isolation resistor. The proposed DGS section is incorporated between the output ports, and the isolation resistor is soldered in parallel with the DGS in the ground plane, instead of on the top plane as in a conventional Wilkinson power divider, to achieve improved or preferable isolation. The proposed design is comprised of two pairs of microstrip transmission lines with equal impedances and varied electrical lengths. The parameters of the main circuit and the DGS section are acquired separately. The parameters of the proposed main circuit are derived by applying conjugate matching theory. Dumbbell-shaped DGS is introduced in the ground plane between the output ports, which acts as a parallel resonator, yielding an attenuation pole at the resonant frequency that contributes to improved isolation. By applying the previous well-known circuit theory, the lumped elements of the equivalent circuit of the DGS were achieved. The physical dimensions of the equivalent circuit for the DGS section were obtained by three-dimensional EM simulation. The measured results show improved isolation, return loss and better bandwidth as compared with other similar works. Furthermore, the proposed circuits designed at resonating frequencies of 3 and 2 GHz presented comparatively good return losses, $S_{11}$ of about −25.54 and −31.24 dB, respectively, and achieved improved isolations, $S_{32}$ between the output ports, in an order of about −40.83 and −36.05 dB, respectively, which is rather exceptional and desirable.

Aerosol jet printing (AJP) outperforms inkjet printing by significantly reducing printed line width, effectively addressing issues such as bulging and surface irregularities. This technology allows for line widths as narrow as 10–100 μm with high aspect ratios, making it well-suited for radio frequency (RF) applications. Consequently, AJP emerges as a valuable tool for direct printing in RF applications. Among conductive inks, silver nanoparticle (Ag-NP) ink is preferred for its straightforward direct printing process and lower sintering temperature requirements. However, the conductivity of printed Ag NP traces falls markedly below that of bulk silver due to significant porosity, limiting its use in RF applications where a high-quality factor is essential. The quality factor of an inductor, indicative of its efficiency in energy storage and release, inversely correlates with its resistance. Our research combines AJP with selective electroplating to reduce the resistance of printed traces, thereby enhancing the inductor’s quality factor for RF applications. We fabricated spiral inductors on alumina substrates using silver NP ink and subsequently applied selective gold electroplating to these traces. This approach led to a significant increase in the inductors’ quality factor, improving it by a factor of 3–5 in the RF frequency range of 100–700 MHz.

The conventional Gysel power divider/combiner uses two shunt resistors to facilitate heat dissipation. Heat sinks are essential for high‐power dividers, to prevent high‐power signals from damaging high‐power resistors and to maintain the power that high power resistors are capable of handling. However, adding a heat sink to a power divider/combiner design using two resistors will increase the total volume of the power divider/combiner. To solve this problem, we have designed and developed a high‐power divider/combiner of 0.5 kW that uses a single series resistor. The Gysel power divider is modified to design the high‐power power divider, and a de‐embedding method was applied to extract the Device Under Test (DUT) of the two‐port high‐power resistor to accurately implement line compensation, achieving magnitude balance within 0.16 dB.