US 12,249,959 B1
Voltage-controlled oscillator with tunable tail harmonic filter
Qiao Yang, Shanghai (CN); and Chi Zhang, Allen, TX (US)
Assigned to GlobalFoundries U.S. Inc., Malta, NY (US)
Filed by GlobalFoundries U.S. Inc., Malta, NY (US)
Filed on Oct. 11, 2023, as Appl. No. 18/484,504.
Int. Cl. H03B 5/12 (2006.01); H03B 5/04 (2006.01); H03B 5/36 (2006.01)
CPC H03B 5/368 (2013.01) [H03B 5/04 (2013.01); H03B 5/1215 (2013.01); H03B 5/1218 (2013.01); H03B 5/1228 (2013.01); H03B 5/1253 (2013.01); H03B 5/1284 (2013.01); H03B 5/129 (2013.01); H03B 2201/0208 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A structure comprising:
an inductor-capacitor resonant circuit including varactors connected to a voltage input node, wherein the voltage input node is connected to receive a variable input voltage;
cross-coupled field effect transistors connected to the inductor-capacitor resonant circuit, wherein the cross-coupled field effect transistors have a shared source node and further have back gates connected to receive a variable back gate bias voltage dependent on the variable input voltage; and
an inductor-capacitor filter connected to the shared source node.