Mixers are commonly used in communication systems for frequency translation, and usually exploit switching in some form to implement multiplication by a square wave. However, at the low supply voltages required for new CMOS technologies, switches are non- or poorly conducting in the "middle voltage range" between the supply voltages. To solve this problem, gates are often driven outside the supply voltage range, but this results in gate-oxide reliability problems, especially in future technologies with very thin oxides. We propose a new CMOS mixer topology that can operate at low supply voltages, without driving gates outside the supply range. It exploits only switches connected to the supplies, just as in digital CMOS inverters. Mixing is achieved exploiting two cross-coupled transconductors, which are alternatingly activated and de-activated by the switches. A down conversion mixer prototype with 12 dB conversion gain was designed and realized in standard 0.18μm CMOS. It achieves satisfactory mixer performance up to 4GHz, at a supply voltage of 1 Volt. Moreover, the mixer topology features a fundamental high frequency noise figure benefit.
|Title of host publication||the 14th ProRisc workshop on Circuits, Systems and Signal Processing (ProRisc 2003)|
|Place of Publication||Utrecht|
|Number of pages||5|
|Publication status||Published - Nov 2003|
|Event||14th ProRISC Workshop on Circuits, Systems and Signal Processing 2003 - Veldhoven, Netherlands|
Duration: 25 Nov 2003 → 27 Nov 2003
Conference number: 14
|Publisher||STW Technology Foundation|
|Workshop||14th ProRISC Workshop on Circuits, Systems and Signal Processing 2003|
|Period||25/11/03 → 27/11/03|
- low voltage design
- communication circuits
Klumperink, E. A. M., Louwsma, S. M., Wienk, G. J. M., & Nauta, B. (2003). Switched Transconductor Mixer Compatible with Future CMOS. In the 14th ProRisc workshop on Circuits, Systems and Signal Processing (ProRisc 2003) (pp. 202-206). Utrecht: STW.