Skip to main content Accessibility help
×
Home
  • Print publication year: 2015
  • Online publication date: June 2015

8 - Intentional circuit compression

from Part II - DPST circuit issues

Summary

Designing circuits for intentional compressed operation is a much rarer task than designing for conventional linear amplifiers. It is no surprise that many of the tools and techniques developed for linear circuit design do not apply to these compressed designs. This chapter goes into the important design details for operation well into the transistor compressed operating regimes. More importantly, details on what is required to actually get to a switching RF power stage are worked out. The design procedures also point out if such a design with the available transistor technology is physically impossible.

Since linear (L-mode) operation, defined in Chapter 4, requires operating within the CCS region of transistor operation, here we de fi ne nonlinear operation as any other mode of operation. This means that both C-mode and P-mode are nonlinear operating regimes. From the operating mode discussion of a 3-port amplifier in Section 4.1.6, C-mode operation is more apparently nonlinear than P-mode. Chapter 6 demonstrates how both of these modes are useful only to intentionally compressed transmitters, just as Chapter 5 showed that both of these nonlinear modes force ET transmitters to violate the fundamental tenets of ET.

Device characteristic curves for both C-mode and P-mode are in the transistor resistive region, away from its CCS region. All locations in the resistive region of the characteristic curves are closer to the I-axis than any part of the CCS region, meaning that transistor power dissipation is always lower in the resistive region than anywhere in the CCS region. This also holds for transistor cut-off (no current) operation, which is a nonlinear operation at the voltage axis, where instantaneous power dissipation is zero. Lower power dissipation corresponds directly to higher energy efficiency. Therefore, nonlinear transistor operation provides better energy efficiency than any linear (meaning continuous current) transistor operation.

Related content

Powered by UNSILO
[8-1] R.Meck, Meck, “Method and Apparatus for Impedance Matching in an Amplifier Using Lumped and Distributed Inductance,” US Patent 7071792, issued July 4, 2006.
[8-2] E.McCune, McCune, “Methods and Apparatus for Controlling Leakage and Power Dissipation in Radio Frequency Power Amplifiers,” US Patent 8364099, issued Jan. 29, 2013.
[8-3] E.McCune, McCune, “High-Efficiency Modulating Amplifier,” US Patent 6636112, issued Oct. 21, 2003.
[8-4] W.Sander, Sander,E.McCune, McCune, and R.Meck, Meck, “Driving Circuits for Switch Mode RF Power Amplifiers,” US Patent 6198347, issued March 6, 2001.
[8-5] E.Oxner, Oxner, “Designing FET Balanced Mixers for High Dynamic Range,” Siliconix Application Note, 1985, available at http://electrooptical.net/www/mixers/EdOx nerHighDynamicRangeFET_Mixers1985.p.
[8-6] R.Meck, Meck,E.McCune, McCune, and L.Burns, Burns, “Constant Impedance for Switchable Amplifier with Power Control,” US Patent 6215355, issued April 10, 2001.
[8-7] R.Meck, Meck, “Method and Apparatus for Impedance Matching in an Amplifier using Lumped and Distributed Inductance,” US Patent 7206553, issued April 17, 2007.
[8-8] J., Sevic and K.Salam, Salam, “Waveform Preshaping for Efficiency Improvement in DC to RF Conversion,” US Patent 6624695, issued Sept. 23, 2003.