Passive Components, Switches Combine High Performance, Fast Availability
By Narda Microwave-East

While MMICs, RFICs, DSP, MEMS, and assorted other tiny devices designed for portable wireless devices get most of the media attention these days, passive components such as power dividers, couplers, and phase shifters, as well as electromechanical and solid-state switches, remain a staple of many commercial wireless systems and military electronic warfare, electronic countermeasures, radar, and communications systems in particular. Narda Microwave-East offers one of the most complete lines of these products with many models available from stock, as well as models customized for virtually any likely performance requirement (Figure 1). These components range in frequency from DC well into the millimeter-wave region.

Power Dividers
Good examples of these products are the company’s four-way power dividers that combine high isolation, low insertion loss, and high amplitude and phase stability and operate from 18 to 40 GHz. The Model 4318-4 has insertion loss of 2.0 dB or less, isolation of at least 14 dB, amplitude balance of 1.2 dB or better, phase balance or 14 deg. or better and input/output VSWR of 1.9:1 or less. It can handle an average RF power input of 30 W into a 1.2:1 VSWR, 5.0 W into a 2:1 VSWR, and 500 mW into an infinite load. It weighs only 1.4 oz (40 g), and can operate over military temperature ranges. Standard RF connectors are 2.92-mm.

The Model 4436 RF power divider covers 500 MHz to 8 GHz and is available in two-way, three-way, four-way, and eight-way versions. The divider combines low insertion loss and high isolation with peak RF power handling up to 1.5 kW. Insertion loss ranges from 1.0 to 1.5 dB in the two-way version (depending on frequency), to 2.0 to 3.0 dB in the three-way version, 1.5 to 4.5 dB in the four-way version, and 2.0 to 8.0 dB in the eight-way version. Isolation is 12 to 20 dB in the two-way version, 12 to 18 dB in the three-way version, and 12 to 17 dB in the four-way and eight-way versions. Phase balance of all versions ranges from 6 to 15 deg. Maximum RF input power is 500 mW CW and 1.5 kW peak and the divider will operate over a temperature range of 0º C to +70º C with humidity up to 95%. The Model 4436 is housed in a rugged aluminum enclosure, weighs between 110 and 650 g depending on the level of power division, and has female SMA RF connectors.

In addition, Narda has developed a broad family of two-way and four-way, multi-octave power dividers that are available with frequency coverage to 33 GHz. Their phase and amplitude tracking characteristics are excellent, and VSWR is very low, with an average value below 1.4:1. There are 14 standard models in the family, each one covering a specific band segment. A good example is the Model 4456-2 two-way power divider, which covers 2 to 18 GHz. From 2 to 8 GHz, it has insertion loss of only 0.5 dB, minimum isolation of 20 dB, amplitude balance of 0.2 dB and phase balance of 3 deg. It will handle 30 W average power into a 1.2:1 VSWR, and 10 W into a 2:1 VSWR.

Couplers
Narda offers a wide range of directional couplers as well, including millimeter-wave models that provide high sensitivity and directivity at frequencies up to 40 GHz. There are four directional couplers in the family. The Model 4018-20 covers 18 to 40 GHz with coupling of 20 dB +/-1.25 dB, frequency sensitivity of +/-0.8 dB, and insertion loss of 1.45 dB, and can handle input powers of 30 W average and 3 kW peak. The Model 4018-10 also covers 18 to 40 GHz, with coupling of 10 dB +/-1.25 dB, frequency sensitivity of +/-0.8 dB, insertion loss of 2.0 dB, and power handling ability of 30 W average and 3 kW peak. Both couplers have maximum input and output VSWR of 1.9:1, directivity of 12 dB, and weigh only 1 oz. The Model 4229-10 (Figure 2) covers 1 to 40 GHz with coupling of 10 dB +/-1.5 dB, frequency sensitivity of +/-1.0 dB, insertion loss of 2.4 dB, and power handling ability of 20 W average and 3 kW peak. Directivity is at least 12 dB and maximum input and output VSWR is 1.75 dB. The couplers are available with either 2.92-mm or 1.85-mm connectors (depending on model).

Narda’s 27000 Series directional couplers are designed for applications in which high levels of RF power are encountered. They handle 400 W average power and 3 or 5 kW peak depending on model. They feature a low-loss air dielectric and operate up to +85º C without degradation. There are six standard models in the family, covering 2 to 8 GHz, 2 to 18 GHz, and 6 to 18 GHz. Coupling is 30, 40, or 50 dB and frequency sensitivity is +/-1.0 dB or less. Directivity ranges from 10 to 16 dB depending on model and maximum insertion loss is as low as 0.25 dB. VSWR is 1.6:1 or better, and all models weigh 425 g. For extremely flat response, Narda offers a family of directional couplers with coverage from 500 MHz to 18 GHz in multi-octave segments. They are small, lightweight, and operate to 105º C without degradation, which makes them well suited for military environments. A good example is the Model 4244-20, which covers 2 to 18 GHz with 20 dB coupling, 20 directivity, 0.4 dB insertion loss, frequency sensitivity of +/-0.4 dB, and average power handling ability of 50 W CW and 3 kW peak.

In the area of phase shifters, Narda offers many models, including the 3752 (Figure 3) that covers 1 to 5 GHz and the Model 3753B, which covers 3.5 to 12.4 GHz. Both have a minimum 180-deg. of phase shift, low VSWR, accuracy of +/-0.5 deg./GHz, handle 200 W average RF power (5 kW peak), and employ type N connectors. The Model 3752 has insertion loss of 0.5 dB or less, VSWR of 1.25:1 or better, and weighs only 4.5 lb. (2 kg). The Model 3753B has insertion loss of 0.7 dB or less, maximum VSWR of 1.35:1 from 3.5 to 10 GHz and 1.4:1 from 10 to 12.4 GHz, and weighs 3.3 lb. (1.5 kg). Narda’s Model 4572B phase trimmer is also a popular device when a small amount of phase shift is required to electrically adjust the length of coaxial cables between (for example) two receivers. It provides phase adjustment of +/1 deg. between 3 and 18 GHz with linearity of +/-2 deg. from 3 to 12.4 GHz and +/-5 deg. from 12.4 to 18 GHz. The device weighs only 19 g and measures 1.6 in. long (with connectors) by 0.32 in. diameter.

Switches
Narda has long been a leader in delivering high-performance electromechanical and PIN-diode switches both from stock or with a high level of customization. The SEM Series (Figure 4), for example, is available from stock in 16 SP2T models that differ in their configurations and features (pulse latching or fail-safe mode, TTL control, with or without suppression diodes, and indicator circuits, among others). They cover DC to 12.4 GHz, DC to 18 GHz and DC to 26.5 GHz.

The SEM 124 break-before-make electromechanical SP2T switch operates from DC to 26.5 GHz, has an operating life of 1 million cycles per position, and is designed to meet MIL-S-3928. Switching time is typically 30 ms or better and it operates from 28 VDC at 160 mA. VSWR ranges from 1.2:1 from DC to 3 GHz to a maximum of 1.7:1 at 26.5 GHz, and maximum insertion loss ranges from 0.2 dB to 3 GHz to 0.7 dB at 26.5 GHz. Minimum isolation is 80 dB to 3 GHz and 50 dB at 26.5 GHz.

Narda offers a wide array of PIN-diode switches, from models optimized for high speed, small size, higher power, and other performance parameters. The company’s miniature drop-in PIN switches have a very slim profile, are available in bands from either 500 MHz to 18 GHz or 2 to 18 GHz in SPST through SP6T as well as transfer types, and as reflective or absorptive configurations. They combine fast switching speed with low insertion loss and are housed in gold-plated, hermetically-sealed packages with removable SMA connectors. All models have integral drivers with reverse voltage protection, and the drivers are TTL compatible. Switching time for reflective types is 15 or 20 ns and 20 or 25 ns for absorptive types depending on model. Insertion loss ranges from 1.2 to 3.8 dB for either type, and isolation is as high as 80 dB. Some reflective types handle 500 mW of power while all other models handle 200 mW.

In each product category, there are many models available from stock, and Narda can provide custom versions with extremely short turnaround times. More information about any of Narda’s passive components and switches can be obtained at www.nardamicrowave.com/east.

NARDA MICROWAVE-EAST
www.nardamicrowave.com
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