Wideband Analog Phase Shifters Cover 2 to 24 GHz

Hittite has developed five new wideband analog phase shifters that are designed to deliver superior performance and innovative features, all within a miniature surface-mount package. These phase shifters—HMC928LP5E, HMC929LP4E, HMC931LP4E, HMC932LP4E and HMC933LP4E—are appropriate for radar systems, satellite communications, EW receivers, amplifier linearization applications and beamforming modules from 2 to 24 GHz.

Figure 1 Typical T/R module diagram.

A primary application of these phase shifters is in radar systems where transmit/receive beamforming modules contain one or more phase shifters in the T/R circuit. The phase shifter supplies the incremental phases to each antenna element, which adjusts the beam in different directions. The reciprocal nature of the phase shifter allows it to be placed in a common path, as illustrated in Figure 1. Therefore, a key requirement for a good phase shifter is reduced phase error and good input/output matching. Given that the phase shifter matching does influence the relative phase shift error, a flat insertion loss curve across the tuning range is essential for accurate phase shift across the 360-degree of phase shift range. The insertion loss curves for the new line of Hittite phase shifters are given in Figure 2.

Another application where these phase shifters are useful is in the area of feed-forward amplifier linearization. Highly linear amplifiers are needed in order to generate the higher data rates and increased spectral efficiency required by microwave radio modulation techniques, such as QPSK, 64 QAM, etc. Linearization is a desirable alternative to backing off a Class A amplifier that would otherwise result in relatively high heat dissipation as well as low power efficiency. These phase shifters can be used to add a variable delay in the feed-forward linearization circuit, as illustrated in Figure 3.

The HMC928LP5E provides a continuously variable phase shift of 0 to 450 degrees from 2 to 4 GHz, with extremely low insertion loss variation versus tuning voltage and frequency. The high accuracy HMC928LP5E is monotonic with respect to control voltage and features very low phase error of ±5 degrees over an octave bandwidth. The HMC928LP5E exhibits typical 3.5 dB insertion loss, accepts an analog control voltage from 0 to +13 V and is housed in a leadless surface-mount QFN 5 × 5 mm package.

The HMC929LP4E provides a continuously variable phase shift of 0 to 430 degrees from 4 to 8 GHz, with extremely consistent insertion loss versus tuning voltage and frequency. The high accuracy HMC929LP4E is monotonic with respect to control voltage and features very low phase error of ±10 degrees across all phase shift ranges over the rated bandwidth. The HMC929LP4E demonstrates a relatively linear phase response as a function of input control voltage, as illustrated in Figure 3. A phase shift range of up to 360 degrees can be achieved with 0 to +9.5 V tuning; a range of up to 430 degrees can be achieved with 0 to +13 V tuning. The HMC929LP4E is housed in a leadless surface-mount QFN 4 × 4 mm package.

The HMC931LP4E is an analog phase shifter that is controlled via an analog control voltage from 0 to +13 V. The HMC931LP4E provides a continuously variable phase shift of 0 to 410 degrees from 8 to 12 GHz, with extremely consistent low insertion loss versus phase shift and frequency. The high accuracy HMC931LP4E is monotonic with respect to control voltage and features a typical low phase error of +12/-7 degrees over a wide bandwidth. The HMC931LP4E is housed in a RoHS compliant 4 × 4 mm QFN leadless package.

The HMC932LP4E is an analog phase shifter that is controlled via an analog control voltage from 0 to +13 V. The HMC932LP4E provides a continuously variable phase shift of 0 to 390 degrees from 12 to 18 GHz, with extremely consistent low insertion loss versus phase shift and frequency. The high accuracy HMC932LP4E is monotonic with respect to control voltage and features a typical low phase error of ±10 degrees over a wide bandwidth. The HMC932LP4E is housed in a RoHS compliant 4 × 4 mm QFN leadless package.

The HMC933LP4E is an analog phase shifter that is controlled via an analog control voltage from 0 to +13 V. The HMC933LP4E provides a continuously variable phase shift of 0 to 470 degrees from 18 to 24 GHz, with extremely consistent low insertion loss versus phase shift and frequency. The high accuracy HMC933LP4E is monotonic with respect to control voltage and features a typical low phase error of ±10 degrees over a wide bandwidth. The HMC933LP4E is housed in a RoHS compliant 4 × 4 mm QFN leadless package.

A summary of the newly released Hittite phase shifters is given in Table 1. Released data sheets for the HMC928LP5E, HMC929LP4E, HMC931LP4E, HMC932LP4E and HMC933LP4E may be found at www.hittite.com. Samples and evaluation PC boards are available from stock and can be ordered via the company's e-commerce site or via direct purchase order.

Hittite Microwave Corp.,
Chelmsford, MA
(978) 250-3343
sales@hittite.com
www.hittite.com