6–18 GHz Broadband GaN SSPA Series: 20 W and 50 W Power Selection Guide

Designing radar, electronic warfare (EW), and wideband test systems requires balancing RF output power against available DC power budgets and subsystem thermal limits. The 6–18 GHz GaN solid-state power amplifier (SSPA) series offers two scalable saturated output power tiers: 20 W (43 dBm, model MCW6018M43A) and 50 W (47 dBm, model MCW6018M47A). Operating continuously from 6000 MHz to 18000 MHz, both modules utilize microelectronic chip-and-wire GaN die assembly inside compact 150 × 90 × 25 mm enclosures. Compared with legacy TWT or GaAs solutions, this scalable 6–18 GHz GaN power amplifier architecture allows systems engineers to select the exact power level required for specific payload constraints.

Maintaining a flat gain response across multi-octave bandwidths is essential for wideband microwave architecture. Flat gain minimizes amplitude calibration errors during rapid frequency sweeps. By mounting bare GaN dies directly using wire-bonding, both modules minimize package parasitics to achieve high power density and predictable RF performance up to 18 GHz.

1. Parameter Comparison and Power Scaling Benchmarks

Selecting between 20 W and 50 W saturated output power depends on system link margins, driver synthesizer capabilities, and available cooling capacity.

Key electrical and mechanical parameters across both modules include:

Technical Parameter	20 W SSPA Module (MCW6018M43A)	50 W SSPA Module (MCW6018M47A)
Operating Frequency Range	6000 MHz to 18000 MHz	6000 MHz to 18000 MHz
Saturated Output Power (Psat)	20 W typical (43 dBm)	50 W typical (47 dBm)
Power Gain	43 dB typical	47 dB typical
Operating Voltage	28 VDC nominal (26 V to 32 V)	28 VDC nominal (26 V to 32 V)
Typical DC Current Draw	3.5 A @ 20 W output power	8.5 A @ 50 W output power
Switching Speed (TON/OFF)	2 µs typical (5 µs max)	2 µs typical (5 µs max)
Input Return Loss	> 10 dB into 50 Ω	> 10 dB into 50 Ω
Spurious Signals / Harmonics	-60 dBc / -10 dBc typical	-60 dBc / -10 dBc typical
Enclosure Dimensions & Mass	150 × 90 × 25 mm; 1.2 kg max	150 × 90 × 25 mm; 1.2 kg max

2. Microelectronic Architecture and Fast Pulse Control

Both power tiers share a unified microelectronic packaging design built for harsh operating environments:

• Chip-and-Wire Assembly: Direct wire-bonding to bare GaN dies eliminates parasitic inductance and capacitance introduced by standard plastic packaging, ensuring smooth gain response across the entire 6–18 GHz band.
• High Power Gain: Typical power gain (43 dB for 20 W, 47 dB for 50 W) reduces drive level requirements. Low-power synthesizers can drive this broadband solid-state power amplifier directly to full saturation.
• Fast Switching Response: Features a rapid RF switch control time (TON/OFF) of 2 µs typical (5 µs maximum). Fast switching enables precise pulse modulation and rapid RF blanking during radar operations and high-speed test sweeps.

3. Telemetry Interface, VSWR Protection, and Thermal Management

A hybrid 7-pin D-Sub connector provides a standardized interface across both power levels for primary DC feeds, logic control, and analog telemetry:

• Pins A1 / A2 (VDD / GND): Primary power feeds supporting DC operating voltages from 26 V to 32 V (28 VDC nominal).
• Pin 1 (ENABLE): TTL logic high (3.3 V) enables RF operation. An internal pull-low circuit keeps the RF stage disabled by default if left floating.
• Pin 2 (CURRENT MONITOR): Provides a real-time analog voltage output relative to drain current (IDD), scaled at 100 mV/A.
• Pin 3 (TEMP MONITOR): Outputs a real-time analog voltage proportional to baseplate temperature, scaled at 10 mV/°C for dynamic thermal tracking.

Field deployments expose power modules to load mismatches caused by cable degradation or antenna decoupling. This broadband power amplifier module series incorporates output matching networks handling a continuous load VSWR of 3:1 across all load phase angles.

Furthermore, both units survive open- or short-circuit conditions (VSWR ∞:1) for up to one minute at full rated power. Thermal management requires an external heatsink (required, not supplied). An internal thermal switch monitors baseplate temperature, disabling internal bias if the baseplate reaches 85 °C. Normal operation restores once the module cools to 60 °C.

Technical Support & Evaluation Options

Need detailed RF specifications, S-parameter files, or 3D CAD models for the 20 W or 50 W modules? Contact our engineering team for full technical documentation and pricing.

Frequently Asked Questions

Q1: How do I determine whether to specify a 20 W or 50 W 6–18 GHz GaN amplifier module?

Base the selection on your available DC power budget and thermal dissipation capacity. The 20 W module draws 3.5 A typical at 28 VDC, making it suitable for SWaP-constrained subsystems. The 50 W module delivers higher output power (47 dBm) for electronic attack or longer-range radar transmitters but draws 8.5 A typical, requiring higher thermal dissipation management.

Q2: What formula converts Pin 2 voltage telemetry to drain current on these modules?

Pin 2 outputs 100 mV per Ampere (0.1 V/A). To calculate drain current (IDD) in amperes, multiply the telemetry voltage by 10: IDD (A) = Voltage (V) × 10. For example, a 0.35 V reading on the 20 W model corresponds to 3.5 A, while a 0.85 V reading on the 50 W model corresponds to 8.5 A.

Q3: Do both the 20 W and 50 W SSPA modules require external heatsinking?

Yes. Both modules require external heatsinking to maintain baseplate temperatures below the 85 °C protection threshold. Because the 50 W model generates higher thermal output due to its 8.5 A DC current draw, its cooling system must provide lower thermal resistance (Rth) or forced-air cooling.