A wave pattern tailoring (WPT) technique performing selective mode excitation is proposed to enable stable multiband operation for standing wave oscillators (SWOs). Multiple standing-wave modes are inherently allowed in an SWO; however, generally only one mode is utilized, while the others are disregarded. To exploit the multimode nature, WPT based on antinode stimulating and terminal reflection switching is proposed and analyzed. By varying the configurations, different standing-wave modes can be activated and stabilized, resulting in multiple oscillation bands. Implemented in a 65-nm CMOS process, the SWO with the proposed WPT technique operates in seven bands centered at 9.3, 22.3, 26.4, 30.4, 41.1, 51.7, and 55.5 GHz, while consuming 9.5-19.8 mW from a 1-V supply. The phase noise measures from -117.7 to -129.2 dBc/Hz at 10-MHz offset, corresponding to figure-of-merit (FoM) from 177.6 to 182.3 dBc/Hz in all bands. The SWO occupies a core area of 0.106 mm2 excluding pads.