Why Embedded Resistors for Phased Array Designs
Phased array antennas depend on precisely matched feed networks. When discrete surface-mount resistors are used in Wilkinson dividers or combiners, solder joint parasitics, placement tolerances, and PCB line-length mismatches create amplitude and phase errors across array elements — historically as much as ±4 dB and ±180° in T/R modules, which traditionally required per-element calibration to correct.
Embedded resistors eliminate these error sources at the material level. Because the resistive element is part of the PCB stackup rather than a discrete component mounted on top of it:
- Parasitic inductance drops from 0.5–1.0 nH (typical SMD) to less than 0.1 nH
- Insertion loss at 40 GHz drops from 0.1–0.2 dB to less than 0.05 dB
- Phase consistency tightens from ±5–10° to approximately ±0.5°
- Board area consumed per resistor drops from 2–10 mm² to effectively zero
The result is a feed network with fewer error sources, more predictable element-to-element behavior, and the ability in symmetric designs to operate without calibration entirely.
Validated Performance in Production Phased Arrays
The most rigorous published validation of Ohmega Ticer embedded resistors in a phased array context is a 2018 IEEE Transactions on Microwave Theory and Techniques paper documenting a 64-element 28 GHz phased array transceiver built on a 12-layer PCB with a Ticer 50 Ω/□ embedded resistive layer used to construct the Wilkinson combiner/divider network. The array achieved 52 dBm saturated EIRP, an 8–12 Gb/s 5G link at 300 meters using 16/64-QAM waveforms, and operated across all scan angles without any calibration — a result the authors attributed directly to the symmetry of the PCB Wilkinson network made possible by embedded resistors.
Additional published results using Ohmega Ticer materials include:
Broadband Wilkinson combiners on LCP
VSWR better than 1.6:1 and isolation greater than 11 dB across 2–18 GHz
Ka-band 3-way power dividers with buried TCR resistors
23.5% bandwidth, transmission loss less than 2 dB, amplitude balance ±0.55 dB at 30–38 GHz
Embedded RF attenuators and equalizers
Validated in measurement to 60 GHz in both coplanar waveguide and stripline configurations
Common Phased Array Applications
Embedded resistors are used throughout phased array architectures, including:
Wilkinson power dividers and combiners
The most common phased array application for embedded resistors, where the isolation resistor is integrated directly into the feed network
Beamforming networks
For 5G base stations and user equipment at 28 GHz and beyond
AESA radar feed networks
In X-band, Ku-band, and Ka-band defense systems
Phased array transceiver modules
For satellite communications and ground stations
R-cards, frequency-selective surfaces (FSS), and high-impedance surfaces (HIS)
Built from etched resistive foil
Embedded RF attenuators and equalizers
for amplitude balancing across the array
Which Ohmega Ticer Products Fit Phased Array Designs
OhmegaPly® (NiP)
Nickel-phosphorus resistive alloy electrodeposited on copper foil. Available in sheet resistivities from 10 to 377 Ω/□. Strong choice for general phased array and beamforming applications where chemical stability and proven heritage are priorities.
TCR® (NiCr / NCAS / CrSiO)
Vacuum-deposited thin film offering tighter temperature coefficient (RTC below 110 ppm/°C for NiCr) and resistor values from 10 ohms to 100k ohms. Used in the IEEE-validated 28 GHz 5G array above.
TCR-EHF®
High-frequency variant using VSP grade copper foil with 2.0 µm Rz matte-side roughness. Engineered specifically for mmWave and high-speed digital applications where insertion loss and impedance stability are critical through millimeter-wave frequencies.
Design Considerations
Embedded resistors in phased array designs require attention to resistor geometry (length-to-width ratio determines resistance value at a given sheet resistivity), via placement (vias should not be placed directly over or near resistor bodies), and Gerber documentation (a second photo-tooling file is required for the etched resistor geometry).
The Ohmega Ticer Design Guide and the resistor calculator spreadsheet in the Technical Library provide the dimensional and tolerance modeling needed for design optimization.
For PCB fabricator coordination and material selection guidance for your phased array application, contact our engineering team.