This manuscript introduces a triple-band power VCO constructed using the complementary PMOS-NMOS (Colpitts) architecture, and it is further based on the transformer tank technique. The proposed design operates in mm-wave and fifth-generation applications, utilizing $130 \mathrm{~nm}$ technology. The triple bands are switched by controlling the secondary varactor capacitor $\left(C_{S}\right)$. The suggested voltage-controlled oscillator (VCO), followed by a common source amplifier, aims to enhance the output power $\left(P_{{out }}\right)$ in dBm. The proposed power VCO delivers an $P_{{out }}$ of 5.1dBm at 35.33GHz. The suggested interleaved square-shaped on-chip transformer exhibits a coupling factor greater than 0.72, along with a substantial quality factor $(Q)$ of 17.8 and 13.6 for the primary and secondary, respectively. The inductances for the primary and secondary are 145 and 289pH. The proposed power Voltage-Controlled Oscillator (VCO) operates in a frequency band between 27.43GHz and 35.33GHz and exhibits a phase noise @ 1MHz offset equal to $-105 \mathrm{dBc} / \mathrm{Hz}$. The Figure of Merit (FoM) is $-187 \mathrm{dBc} / \mathrm{Hz}$, and the peak achieved $P_{{out }}$ is 5.1dBm. Finally, the power VCO’s die size is $0.11 \mathrm{~mm}^{2}$, while the whole chip size is $0.27 {mm}^{2}$.