X-Band 256-Channel AESA Antenna: 16×16 Array, RF Specifications, and Radar Integration

On platforms constrained by size, weight, power, and cost (SWaP-C), deploying active electronically scanned arrays (AESA) on mid-sized mobile platforms, tactical ground vehicles, and unmanned aerial vehicles (UAVs) requires balancing spatial resolution and detection range against strict payload limits. Oversized antenna panels can strain thermal management systems and exceed vehicle payload capacity.

The 256-channel X-band 2D active phased array antenna addresses these constraints through a 16×16 active phased-array architecture integrating 256 radiating elements into an Antenna-in-Package (AiP) layout. Operating across the 9.2 GHz to 9.8 GHz frequency range, the specified system EIRP is ≥ 80 dBm over the nominal operating band, while maintaining a normal transmit beamwidth of 5.8° ± 0.3° with a specified maximum power consumption of ≤ 235 W at a 20% transmission duty cycle. Weighing ≤ 3.5 kg with a profile depth of ≤ 60 mm, the assembly integrates T/R phase and amplitude control, monopulse sum-and-difference feed networks, a frequency synthesizer, and beam-control electronics into a single unified chassis.

With a specified beam-switching time of ≤ 50 µs and synchronous serial control over differential RS-422 signaling, the architecture supports rapid beam repositioning for search and tracking operations.

1. 16×16 Matrix Topology and SWaP-C Payload Optimization

In mobile surveillance and airborne tactical tracking, array mass, volume, and power consumption can directly affect platform payload capacity and endurance. The 256-channel active phased array utilizes a uniform 16×16 planar grid layout engineered to optimize gain density while maintaining a low physical profile.

The 256-channel configuration prioritizes a compact SWaP-C envelope while providing the specified beamwidth, scan range, and EIRP for system integration.

• Payload Weight & Profile: Weighing ≤ 3.5 kg with dimensions of ≤ 315 × 315 × 60 mm, the panel provides a compact form factor for integration into UAV payloads, tactical masts, and vehicle-mounted systems, subject to platform-level mechanical and thermal constraints.
• Power & Thermal Loading: Specified maximum power consumption of ≤ 235 W (at 20% transmission duty cycle) helps reduce the power and thermal-management burden on the host platform.
• Operating Range: The array accepts DC 18V–36V input (nominal +24V DC) and has a specified operating temperature range of -40°C to +70°C.

2. Antenna-in-Package (AiP) Architecture and System Signal Flow

The panel uses an Antenna-in-Package (AiP) architecture integrating the antenna aperture, active T/R channels, monopulse feed network, and beamformer directly within the 60 mm chassis cavity.

• System EIRP, Gain, and G/T: The 256-channel active aperture provides a specified system EIRP of ≥ 80 dBm over the nominal operating band. On the receive path, active channel gain provides ≥ 15 dB (adjustable) with a receiver noise figure under 3.5 dB, achieving a specified system G/T of ≥ 0.5 dB/K.
• Integrated Enclosure: The monopulse sum-and-difference feed matrix, frequency synthesizer, power distribution, and beam controller sit within the conductive oxide-coated cavity. This reduces the need for external RF cabling between major RF sub-assemblies.

System Signal Flow:

1. Specified Tx/Rx Excitation Input: The array is specified for a single-channel Tx/Rx excitation input of ≥ 27 dBm via primary SMA-K Port H.
2. Unified AiP Matrix (60 mm Depth): The 16×16 active array provides per-channel phase and amplitude control for beamforming across the aperture.
3. Monopulse Sum-and-Difference Network: Embedded feed lines process received signals to generate Azimuth Difference (FWC) and Elevation Difference (FYC) outputs directly at dedicated SMA-K ports.
4. Digital Control & Power Interface: Command frames pass through the J30J-15ZK control connector, while DC power feeds through a dedicated J30J04P04P connector.

3. Beam Steering Agility and Monopulse Tracking Performance

Electronic scan coverage spans ±45° in azimuth and ±45° in elevation, with a typical difference-beam null depth of -22 dB across both planes.

Steering Agility and Pointing Accuracy

• Electronic Scan Range: Azimuth ±45° / Elevation ±45°.
• Scan Gain Roll-Off: ≤ 3 dB over the specified ±45° scan range.
• Angular Pointing Error: ≤ 0.15° within ±20° steering and ≤ 0.3° across the full ±45° scan range.
• Beam Switching Time: Specified at ≤ 50 µs.

A specified beam-switching time of ≤ 50 µs supports rapid beam repositioning between search, tracking, and other interleaved operating modes.

Monopulse Sum-and-Difference Characteristics

The internal feed network generates sum and orthogonal difference beams to supply angular error discriminant signals to the radar receiver:

• Transmit Beamwidth: 5.8° ± 0.3° at center frequency (Azimuth & Elevation).
• Receive Beamwidth: 6.8° ± 0.4° at center frequency (Azimuth & Elevation).
• Receive First Sidelobe Level: < -22 dB in the normal direction.
• Difference Beam Null Depth: -22 dB (typical, Azimuth & Elevation).

4. RF and Electrical Specifications Table

The following table summarizes the key RF, beam-steering, and electrical parameters for system-level evaluation of X-band monopulse tracking arrays:

Technical Parameter	Specification / Requirement
Operating Frequency Band	9.2–9.8 GHz (30 MHz frequency steps)
Array Topology	256 Elements (16×16 Matrix)
Polarization	Vertical (Horizontal available upon request)
System EIRP (Normal)	≥ 80 dBm
System G/T	≥ 0.5 dB/K
Electronic Scan Range	Azimuth ±45° / Elevation ±45°
Pointing Accuracy	≤ 0.15° (within ±20°) / ≤ 0.3° (within ±45°)
Scan Gain Roll-Off	≤ 3 dB (within ±45° scan range)
Tx Normal Beam Width	5.8° ± 0.3° (@ center frequency)
Rx Normal Beam Width	6.8° ± 0.4° (@ center frequency)
Difference Beam Null Depth	-22 dB (Typical, Azimuth & Elevation)
First Sidelobe Level (Rx)	< -22 dB (Normal direction)
Tx/Rx Excitation Input	≥ 27 dBm (Single-channel input)
Rx Active Channel Gain	≥ 15 dB (Adjustable)
Receiver Noise Figure	< 3.5 dB
Beam Switching Time	≤ 50 µs

5. Mechanical, Power, and Interface Configurations

Designed for tactical and mobile platform integration, all RF, power, control, and telemetry interfaces are located on the rear chassis.

Parameter	Specification / Requirement
Dimensions (L × W × H)	≤ 315 × 315 × 60 mm (Excluding connectors)
System Weight	≤ 3.5 kg
Power Supply Input	DC 18V–36V (Nominal +24V)
Max Power Consumption	≤ 235 W (At 20% transmission duty cycle)
RF Interfaces	Port H (Tx/Rx excitation input); Port FWC (Azimuth difference output); Port FYC (Elevation difference output)
Power Connector	J30J04P04P (Pins A/B: +24V, Pins C/D: GND)
Control Connector	J30J-15ZK (Synchronous RS-422 protocol)
Operating Temperature	-40°C to +70°C
Surface Finish	Conductive oxide coating (Cavity) / White primer (Radome)

6. Synchronous RS-422 Control Protocol & Telemetry

Digital beam control uses a synchronous serial interface over differential RS-422 signaling, with an external clock of ≥ 10 MHz, supporting deterministic command timing.

• Data Link Format: Synchronous RS-422 with a clock frequency of ≥ 10 MHz.
• Beam-Control Tx Frame (Controller → Array): 16-byte payload (0x10) carrying Message Type (0x13), frequency encoding, Tx/Rx switching control, Azimuth/Elevation angle encoding (0.05° quantization step), and beam/channel configuration.
• Telemetry Rx Frame (Array → Controller): 36-byte telemetry payload (0x24) carrying Message Type (0x32), array temperature readings, current draw measurements, and PWM fan status.

7. OEM/ODM Customization Parameters

The standard panel operates across 9.2 GHz–9.8 GHz with vertical polarization. For specialized platform integration of high-EIRP active phased array modules or the 256-channel X-band 2D active phased array antenna, customizable OEM/ODM parameters include:

1. Operating frequency sub-bands and bandwidth requirements
2. Polarization options (Horizontal polarization available upon request)
3. Custom mechanical mounting footprints and connector orientations
4. Customized beam-steering protocol frames or interface bridges

Frequently Asked Questions

Q1: What is the primary operational advantage of the 256-channel 16×16 AiP topology?

The 16×16 matrix integrates 256 active elements into a panel weighing ≤ 3.5 kg with a profile depth of ≤ 60 mm. It delivers a specified system EIRP of ≥ 80 dBm and a transmit beamwidth of 5.8° ± 0.3° while capping max power consumption at ≤ 235 W at a 20% duty cycle, making it suitable for payload-constrained UAVs and mobile platforms.

Q2: What is the specified electronic scan coverage and beam switching speed?

The array provides ±45° electronic scanning in both azimuth and elevation planes with scan gain roll-off ≤ 3 dB. Beam switching executes in ≤ 50 µs.

Q3: What excitation drive power does the array require?

The array specifies a single-channel Tx/Rx excitation input of ≥ 27 dBm at SMA-K Port H. The resulting system EIRP is specified at ≥ 80 dBm.