Title :
A high IIP2 downconversion mixer using dynamic matching
Author :
Bautista, Edwin E. ; Bastani, Babak ; Heck, Joseph
Author_Institution :
Motorola Labs., Plantation, FL, USA
Abstract :
This paper presents an RF downconversion mixer with improved rejection to second-order intermodulation for RF application within a direct-conversion receiver requiring high input blocking performance. The mixer, implemented in a 2.7-V 0.35-/spl mu/m BiCMOS process, achieves a second-order input intercept point of at least +72 dBm for a BiCMOS design and at least +66 dBm for an all-CMOS design. The design utilizes dynamic matching to enhance the balance of a fully differential mixer through mitigation of both component and device mismatches. In addition, dynamic matching is shown to improve the mixer´s 1/f noise performance. For an all-CMOS mixer design, a 30-dB improvement in the mixer´s noise floor at 1 kHz has been observed compared to conventional fully differential CMOS Gilbert-cell mixer. Additionally, background is given on second-order intermodulation and on system IIP2 requirements for a direct-conversion receiver.
Keywords :
1/f noise; BiCMOS analogue integrated circuits; CMOS analogue integrated circuits; UHF integrated circuits; UHF mixers; impedance matching; integrated circuit noise; intermodulation distortion; radio receivers; 0.35 micron; 1/f noise performance; 2.7 V; 815 MHz; BiCMOS mixer design; CMOS mixer design; RF downconversion mixer; direct-conversion receiver; dynamic matching; fully differential mixer; high IIP2 downconversion mixer; high input blocking performance; second-order IMD; second-order input intercept point; second-order intermodulation rejection; Bandwidth; Baseband; BiCMOS integrated circuits; Degradation; Filters; Intermodulation distortion; Nonlinear distortion; RF signals; Radio frequency; Signal generators;
Journal_Title :
Solid-State Circuits, IEEE Journal of
