RF phase shifters

01

Choose digital steps or voltage-variable control

MACOM's MAPS-011021 is a GaAs pHEMT 6-bit digital phase shifter with an integrated driver: bits of 5.625°, 11.25°, 22.5°, 45°, 90° and 180° give 0° to 360° in 5.625° steps, under serial or parallel control, at 50 Ω in a 6 mm 28-lead PQFN, for 900–1,200 MHz test and EW use. [1]

Mini-Circuits' JSPHS-2484+ is a 50 Ω voltage-variable phase shifter giving 180° over 2,150–2,484 MHz, with insertion loss of 2.0 dB (typ.), VSWR of 1.5:1 (typ.), 20 dBm maximum RF input, a 28 V control-voltage rating and −40 to 85 °C operation. [2]

Editorial calculation: a 6-bit shifter divides 360° into 2⁶ = 64 states, so 360 ÷ 64 = 5.625°; the nearest settings to 100° are 17 steps (95.625°) and 18 steps (101.25°), leaving up to half a step, about 2.8°, of quantisation error before device error. [1]

Give the supplier the frequency band, phase range and step size or control-voltage range, required phase and amplitude accuracy across states and temperature, insertion loss limit, power level and linearity, switching or settling time, control interface, package or connectors, and quantity.

02

Check phase error, loss variation, settling and power

MACOM specifies the MAPS-011021 at 0.9–1.2 GHz with insertion loss of 3.5 dB (typ.) and 3.8 dB maximum in any state, peak-to-peak attenuation variation of 0.5 dB maximum across all phase states, RMS attenuation error of 0.15 dB, RMS phase error of 2.0° (typ.), VSWR 1.5:1, 1 dB compression of 29 dBm, input IP3 of 42 dBm, 25 dBm maximum operating power, and phase settling of 90 ns on and 110 ns off to within ±1° of final phase. RMS values are calculated across all 64 states relative to the 0° state. [1]

Editorial note: the same datasheet's description quotes 1.5° RMS phase error while its specification table gives 2.0° (typ.), so use the table value for design and ask the supplier which applies. Its per-bit table also shows bit accuracy, for example the 180° bit measuring 173.5–181.5°. [1]

03

Weigh finer phase steps against loss and settling time

pSemi lists the PE44820 as an 8-bit digital phase shifter for phased-array and active-antenna use, covering 358.6° in 1.4° steps across 1.7–2.2 GHz, with extended narrow-band operation from 1.1 to 3.0 GHz, bits of 180°, 90°, 45°, 22.5°, 11.2°, 5.6°, 2.8° and 1.4°, serial or parallel programming and a 32-lead 5 × 5 × 0.85 mm QFN package. [4]

Its specification table gives insertion loss of 6 dB (typ.), 60 dBm IIP3, 1° RMS phase error, 0.1 dB RMS amplitude error, 365 ns settling time, a 2.3–5.5 V supply range and a 500 V HBM ESD rating; its key features list +105 °C operating temperature. [4]

Editorial calculation: 8 bits give 2⁸ = 256 states and 360 ÷ 256 = 1.40625°, so 255 steps reach about 358.6° and the worst-case quantisation error is about 0.7°, a quarter of the 2.8° of the 6-bit part above. Against MACOM's 6-bit MAPS-011021 (3.5 dB loss (typ.), 90 ns on and 110 ns off settling), comparing the (typ.) loss values the finer steps come with 2.5 dB more loss and about 3.3 to 4 times the settling time, in a different band. [4] [1]

If you need steps finer than 5.625°, ask for the bit count, measured RMS phase and amplitude error across all states, insertion loss and settling time in your band.

04

Compare connectorised digital phase shifters across bands

Qualwave's catalogue page for digital-controlled phase shifters lists connectorised units from 0.2 to 40 GHz by frequency band, phase range, control bits, step, maximum VSWR and maximum insertion loss, and its phase shifter overview states units to 50 GHz overall, manual phase adjustment up to 900°/GHz and average power handling up to 100 W. [3]

Broadband connectorised modules trade much higher insertion loss for band coverage compared with the narrow-band surface-mount part above (3.8 dB maximum over 0.9–1.2 GHz), so the loss has to be budgeted in the RF chain. [3] [1]

Editorial calculation: a 6-bit shifter over 360° has 64 states of 5.625°; an insertion loss of 18 dB passes about 1.6% of input power.

State the band, required phase resolution and range, acceptable insertion loss and VSWR, connector type and power level, and ask for measured phase and loss across all states and the band.

05

Connectorised, voltage-controlled and RF-component sources

Qualwave, whose catalogue supplies the connectorised table above, lists manual, digital and voltage-controlled phase shifters; Advanced Microwave Technologies lists voltage-controlled phase shifters with waveguide and coaxial parts; Hisiwell lists phase shifters with other RF components.

Ask any supplier for measured phase and amplitude across all states and the band, RMS phase and attenuation error, insertion loss, VSWR, P1dB and IP3, switching or settling time, control logic and voltage, temperature drift, and package or connector options.

06

Bits, control network, driver, matching and package

07

Band, phase range, loss and settling values to specify

The rows quote two single parts, a 6-bit digital shifter and a 180° analog one, so loss and phase error are per device; for broadband connectorised modules use the loss row at the end. [1] [2] [3]

08

Send the RF, control and accuracy data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

RF: [band; power; impedance]
Phase: [range; step or voltage range; accuracy]
Amplitude: [loss; variation across states]
Speed: [settling time]
Control: [serial or parallel; supply]
Package: [SMT; die; connectors]

See manufacturer records Send an enquiry through CNFX