Overcoming SWaP-C and Narrow-Beam Resolution Trade-Offs in Tactical X-Band Radar Systems

When designing vehicle-mounted air defense pedestals, tactical airborne pods, or counter-UAS surveillance radars, systems engineers face a common hardware trade-off: how to achieve long-range target illumination and fine angular resolution without exceeding strict weight, depth, and prime power constraints.

Traditional reflector antennas capable of producing narrow beamwidths can impose significant volumetric, mechanical, and installation constraints. Conversely, scaling up planar active arrays often introduces chassis depth and cabling complexity.

The X-band 1024-channel 2D active phased array antenna addresses these integration requirements through a highly integrated 32×32 Antenna-in-Package (AiP) matrix. Operating across 9.2 GHz to 9.8 GHz (with typical 30 MHz steps), the subsystem delivers an EIRP of ≥ 92 dBm, a G/T sensitivity of ≥ 6.5 dB/K, and a transmit normal beamwidth of 2.8° ± 0.3° within a compact 65 mm depth profile and a total weight of ≤ 14 kg.

Engineering Specifications

The complete RF, dynamic scanning, electrical, and mechanical parameters of the 1024-channel array are summarized below:

Parameter Category	Technical Parameter	Specification / Requirement
RF & Array Topology	Operating Frequency Band	9.2 GHz – 9.8 GHz (Typical Step: 30 MHz)
	Array Topology	32 (Azimuth) × 32 (Elevation) = 1,024 Elements
	Polarization Method	Vertical (Horizontal customization available)
	System EIRP (Normal Direction)	≥ 92 dBm (Across all bands/temps)
	G/T Sensitivity (Normal Direction)	≥ 6.5 dB/K (Across all bands/temps)
	Receiver Noise Figure	< 3.5 dB (Across all bands/temps)
	Rx Active Channel Gain	≥ 15 dB (Design guarantee; adjustable)
	Transmitter Excitation Power	25 ± 2 dBm
Beam Pattern & Steering	Electronic Scan Range	Azimuth ±45° / Elevation ±45°
	Scan Gain Roll-Off	≤ 3 dB (within ±45° scan range)
	Pointing Accuracy	≤ 0.15° (within ±20°) / ≤ 0.3° (within ±45°)
	Tx Normal Beam Width	2.8° ± 0.3° (@ center frequency)
	Rx Normal Beam Width	3.6° ± 0.4° (@ center frequency)
	Receive 1st Sidelobe Level	≤ -22 dB (Normal direction)
	Difference Beam Null Depth	-22 dB (Typical, Azimuth & Elevation)
	Beam Switching Speed	≤ 70 μs
SWaP-C & Environmental	Dimensions (L × W × H)	≤ 600 × 630 × 65 mm
	System Weight	≤ 14 kg
	Power Supply Input	DC 18V – 36V
	Max Power Consumption	≤ 1000 W (At 20% transmission duty cycle)
	Operating Temperature	-40°C to +70°C
	Surface Finish	Conductive oxide coating (Cavity) / White primer (Radome)

32×32 AiP Matrix and Spatial Beamforming Performance

The array integrates radiating elements, multichannel T/R channels, frequency synthesis, and monopulse comparators into a unified low-profile assembly:

• High EIRP (≥ 92 dBm): The 1,024-element array specifies a normal-direction system EIRP of ≥ 92 dBm with a transmitter excitation power of 25 ± 2 dBm.
• Narrow Beamwidth Resolution: The 32×32 grid synthesizes a 2.8° ± 0.3° transmit beam and a 3.6° ± 0.4° receive beam at center frequency, improving spatial angular resolution for radar target discrimination.
• Receiver Sensitivity: The active receive channel gain is specified at ≥ 15 dB with a receiver noise figure of < 3.5 dB, while the normal-direction system G/T is specified at ≥ 6.5 dB/K. The receive first sidelobe level is ≤ -22 dB in the normal direction.

Electronic Steering and Monopulse Tracking

Eliminating mechanical positioning drives enables agile volume search and continuous target tracking:

• Two-Dimensional ±45° Scanning: Electronic phase shifting across the 1,024 elements steers the beam across ±45° in azimuth and elevation, with scan gain roll-off constrained to ≤ 3 dB within the scanning sector.
• Pointing Precision: The system achieves an angular pointing accuracy of ≤ 0.15° within the central ±20° sector and ≤ 0.3° across the full ±45° boundary.
• ≤ 70 μs Beam Switching Speed: The internal wave controller supports beam switching speeds of ≤ 70 μs for rapid beam-state transitions in dynamic tracking applications.
• Dedicated Monopulse Outputs: RF signals break out via dedicated SMA-K connectors for Sum (H), Azimuth Difference (FWC), and Pitch Difference (FYC) channels, providing a typical difference-beam null depth of -22 dB.

Hardware Interface and System Integration

To simplify integration into mobile and airborne radar architectures, the subsystem provides standardized mechanical, digital, and power interfaces:

• RF Connections: Three SMA-K female connectors provide dedicated paths for H (Tx/Rx Excitation), FWC (Azimuth Diff), and FYC (Pitch Diff).
• Control & Telemetry (J30J-15ZK): Operates on a Synchronous RS422 serial bus (clock rate ≥ 10 MHz) supporting deterministic 16-byte wave-control packets (0.05° angular quantization, 1024-channel switch matrix) and 36-byte telemetry status packets (16-byte temperature data, 16-byte current data, PWM fan status).
• Primary DC Power (4 Sets of J30J04P040): Distributes current across internal boards from a DC 18V–36V supply (A/B: +24V, C/D: GND), consuming ≤ 1000 W at a 20% transmit duty cycle.
• Thermal Management: A dedicated PHB 2.0 connector provides PWM regulation for up to 4 fan groups, supporting thermal management within the specified -40°C to +70°C operating range.

Primary Application Scenarios

System integrators incorporate active phased array antennas of this class across several demanding defense and surveillance roles:

• Mobile Air Defense & C-UAS Pedestals: Vehicle-mounted 2D search and angular tracking of dynamic aerial targets using narrow pencil beams.
• Tactical Airborne Radar Pods: Search and surface-tracking payloads for UAVs and aircraft requiring a depth profile under 65 mm and system weight under 14 kg.
• Perimeter & Coastal Surveillance: Continuous 2D sector monitoring with simultaneous three-channel monopulse angular measurement.
• Precision Fire-Control Networks: Fast beam repositioning and narrow beam illumination for target tracking within fire-control architectures.

Technical Evaluation and Integration Inquiries

When evaluating modern phased array antenna systems for radar platforms, engineering teams can request technical documentation and configuration support to evaluate compatibility:

• Interface Control Documents (ICD): Pinout definitions for the J30J-15ZK digital interface, power connector wiring schematics, and packet validation structures.
• 3D Mechanical Models (STEP): Exact mounting patterns, center of gravity (CG), and thermal clearance data for pod and mast installations.
• Customization Options: Inquiries regarding horizontal polarization options and custom frequency step intervals.

Frequently Asked Questions

Q1: What are the primary RF power and excitation specifications for this 1024-channel array?

The 32×32 AiP architecture integrates 1,024 active transceiver channels within the planar aperture. The system specifies a transmitter excitation power of 25 ± 2 dBm and a normal-direction EIRP of ≥ 92 dBm, providing the required RF output performance for the target radar architecture.

Q2: What hardware interfaces are provided for RF signals and wave control?

RF connections use three dedicated SMA-K ports for Sum (H), Azimuth Difference (FWC), and Pitch Difference (FYC). Digital wave control and telemetry operate via a J30J-15ZK connector using Synchronous RS422 (clock ≥ 10 MHz), and power is delivered via four sets of J30J04P040 connectors.

Q3: What is the beam switching speed and pointing accuracy across the scan range?

The array achieves a beam switching speed of ≤ 70 μs. The electronic beam pointing accuracy is specified at ≤ 0.15° within the central ±20° scan cone and ≤ 0.3° across the full ±45° scan range.