Phase shift module
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(Redirected from Phase shifter)
This article is about the microwave device. For the guitar effect, see Phaser (effect).
"Phase shifter" redirects here. For the type of electric utility transformer, see quadrature booster.
- Active versus passive: Active phase shifters provide gain, while passive phase shifters are lossy.
- Analog versus digital:
- Analog phase shifters provide a continuously variable phase shift or time delay.
- Digital phase shifters provide a discrete set of phase shifts or time delays. Discretization leads to quantization errors. Digital phase shifters require parallel bus control.
- Differential, single-ended or waveguide:
- Differential transmission line: A differential transmission line is a balanced two-conductor transmission line in which the phase difference between currents is 180 degrees. The differential mode is less susceptible to common mode noise and cross talk.
- Single-ended transmission line: A single-ended transmission line is a two-conductor transmission line in which one conductor is referenced to a common ground, the second conductor. The single-ended mode is more susceptible to common-mode noise and cross talk.
- Antenna selection: double folded slot (DFS), microstrip, monopole
- Examples: CPW, microstrip, stripline
- Antenna selection: waveguide, horn
- Frequency band
- One-conductor or dielectric transmission line versus two-conductor transmission line
- One-conductor or dielectric transmission line (optical fibre, finline, waveguide):
- Two-conductor transmission line (CPW, microstrip, slotline, stripline):
- Differential or single-ended
- TEM or quasi-TEM mode is TTD or quasi-TTD
- Phase shifters versus TTD phase shifter
- A phase shifter provides an invariable phase shift with frequency, and is used for fixed-beam frequency-invariant pattern synthesis.
- A TTD phase shifter provides an invariable time delay with frequency, and is used for squint-free and ultra wideband (UWB) beam steering.
- Reciprocal versus non-reciprocal
- Reciprocal: T/R
- Non-reciprocal: T or R
- Distorted if lumped
- Undistorted and TTD if distributed
- Applications: reflect arrays (S11 phase shifters)
- Distorted if S21 phase shifter, because of 3 dB coupler
- Undistorted and TTD if S11 phase shifter
- High-pass or low-pass
- or T
- Undistorted if the left-handed high-pass sections cancel out the distortion of the right-handed low-pass sections
- Applications: UWB beam steering
- Distortion: undistorted and TTD
- Vector summing
Figures of Merit
- # Effective bits, if digital [Bit]
- Biasing: current-driven, high-voltage electrostatic [mA,V]
- DC power consumption [mW]
- Distortion: group velocity dispersion (GVD) [ps/(km.nm)]
- Gain [dB] if active, loss if [dB] if passive
- Linearity: IP3, P1dB [dBm]
- Phase shift / noise figure [deg/dB] (phase shifter) or time delay / noise figure [ps/dB] (TTD phase shifter)
- Power handling [mW, dBm]
- Reliability [Cycles, MTBF]
- Size [mm2]
- Switching time [ns]
- Microwave Solid State Circuit Design, 2nd Ed., by Inder Bahl and Prakash Bhartia, John Wiley & Sons, 2003 (Chapter 12)
- RF MEMS Theory, Design and Technology by Gabriel Rebeiz, John Wiley & Sons, 2003 (Chapter 9-10)
- Antenna Engineering Handbook, 4th Ed., by John Volakis, McGraw-Hill, 2007 (Chapter 21)
- Phased Array Antennas, 2nd Ed., by R. C. Hansen, John Wiley & Sons, 1998
- Phased Array Antenna Handbook, 2nd Ed., by Robert Mailloux, Artech House, 2005
- Phased Array Antennas by Arun K. Bhattacharyya, John Wiley & Sons, 2006
- Microwave Phase Shifter information from Herley General Microwave