This paper presents a 32-element 25.8-to-30.8 GHz phased-array CMOS transmitter (TX) with programable piecewise linear temperature-compensation (TC) technique to counteract the increase and decrease in gain under high and low-temperature conditions, maintaining a constant gain within the operational temperature range of the system. The proposed TX is composed of four chips, which consists of a common channel with the TC block and eight elements. The chip is fabricated in 65nm CMOS process, exhibiting a 25.4 dB peak gain and 5 GHz bandwidth (BW) from 25.8-to-30.8 GHz. The measured OP1dB and saturation power are 11.6 dBm and 13.4 dBm, respectively. The corresponding PAE at the OP1dB and Psat are 18.8% and 26.4% at 28GHz, respectively. Results of temperature-variable gain showed ±0.002 dB/°C gain variation over a range of -60-to-85 °C.