Inventor
OHATA KEIICHI
JP27 patents
⚠️ This page may combine multiple inventors who share the name “OHATA KEIICHI”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
NEC CORP
20 patentsUS6774748B1Aug 10, 2004
RF package with multi-layer substrate having coplanar feed through and connection interface
NEC CORP125 citations98
US6320543B1Nov 20, 2001
Microwave and millimeter wave circuit apparatus
NEC CORP136 citations98
US6674347B1Jan 6, 2004
Multi-layer substrate suppressing an unwanted transmission mode
NEC CORP70 citations96
US6518864B1Feb 11, 2003
Coplanar transmission line
NEC CORP63 citations96
US4727403AFeb 23, 1988
Double heterojunction semiconductor device with injector
NEC CORP105 citations95
US7170373B2Jan 30, 2007
Dielectric waveguide filter
NEC CORP26 citations92
US6903700B2Jun 7, 2005
High frequency circuit substrate and method for forming the same
NEC CORP23 citations92
US4556895ADec 3, 1985
Field-effect transistor having a channel region of a Group III-V compound semiconductor and a Group IV semiconductor
NEC CORP32 citations92
US7378925B2May 27, 2008
Dielectric resonator, dielectric resonator frequency adjusting method, and dielectric resonator integrated circuit
NEC CORP11 citations84
US7196598B2Mar 27, 2007
Dielectric waveguide filter with inductive windows and coplanar line coupling
NEC CORP12 citations84
US6437654B2Aug 20, 2002
Substrate-type non-reciprocal circuit element and integrated circuit having multiple ground surface electrodes and co-planar electrical interface
NEC CORP16 citations84
US5026655AJun 25, 1991
Process of fabricating a heterojunction field effect transistor
NEC CORP10 citations74
US4948751AAug 14, 1990
Moelcular beam epitaxy for selective epitaxial growth of III - V compound semiconductor
NEC CORP16 citations74
US4903091AFeb 20, 1990
Heterojunction transistor having bipolar characteristics
NEC CORP17 citations74
US5111256AMay 5, 1992
High speed semiconductor device and an optelectronic device
NEC CORP14 citations73
US4839703AJun 13, 1989
High speed and power transistor
NEC CORP15 citations73
US7710216B2May 4, 2010
Balun circuit and integrated circuit device
NEC CORP7 citations70
US8045580B2Oct 25, 2011
Band control method and communication apparatus
NEC CORP5 citations62
US4837605AJun 6, 1989
Indium-phosphide hetero-MIS-gate field effect transistor
NEC CORP2 citations62
US7113060B2Sep 26, 2006
Dielectric waveguide filter with inductive windows and coplanar line coupling
NEC CORP0 citations52
E THERMOGENTEK CO LTD
4 patentsUS12274170B2Apr 8, 2025
Thermoelectric power-generation module, wearable biological-body-sensing device, biological-body location detection system
E THERMOGENTEK CO LTD0 citations46
US11674733B2Jun 13, 2023
Cold insulation container
E THERMOGENTEK CO LTD0 citations46
US12262638B2Mar 25, 2025
Tubular heat exchanger with thermoelectric power generation function
E THERMOGENTEK CO LTD0 citations42
US10680154B2Jun 9, 2020
Thermoelectric conversion module, method for producing same, thermoelectric power generation system, and method for producing same
E THERMOGENTEK CO LTD0 citations33