How to Design Patch Antenna for Millimeter-Wave 5G NR

Overview of Technical Issues:

The radiating patch element provides insufficient bandwidth generation (typically 2-5% for conventional designs) to cover the required 5G NR millimeter-wave channel bandwidth (several hundred MHz at 24-40 GHz bands), while the feeding structure delivers insufficient impedance matching across the operating range causing excessive reflection losses at band edges; these functional insufficiencies result in inability to maintain stable radiation performance across the required 5G frequency channels, limiting practical deployment for millimeter-wave 5G NR applications.

Solution directions generated for this problem

Problem Direction 1 :

ImprovePatch resonance bandwidth
VS
ConstraintAntenna element physical dimensions

Inspiration 1 : Cross-domain reference

Application Principle: #17 Another dimension (Dimensionality change)
Cross-domain applicability Assess applicability
Shaped aperture set for multi-beam array configurations
Innovative Solution Refine solution

Vertically-stacked dual-patch resonator with aperture coupling for wideband millimeter-wave operation

Stack two patches vertically in substrate
How to solve :
  • Fabricate dual-layer substrate stack: bottom layer Rogers RO4003C (εr=3.55, h1=0.508mm) with driven patch, top layer Rogers RO3003 (εr=3.00, h2=0.254mm) with parasitic patch, total thickness 0.762mm
  • Design H-shaped aperture slot (dimensions 1.2mm×0.4mm with 0.6mm center bar) in shared ground plane between layers to achieve electromagnetic coupling coefficient k=0.15-0.25, generating dual resonances spaced 8-12% apart
  • Optimize patch size ratio: driven patch 3.2mm×3.2mm, parasitic patch 3.0mm×3.0mm, maintaining <5mm footprint while vertical coupling merges resonances into >10% combined bandwidth at 28 GHz center frequency
Expected Effect : Bandwidth 12-15% (3.4-4.2 GHz at 28 GHz), footprint ≤4.5mm, gain 6-7 dBi
Risk Control :
  • aperture slot fabrication tolerance ±20μm
  • layer-to-layer alignment error <50μm
  • substrate bonding air gap control

Problem Direction 2 :

ImproveImpedance matching bandwidth
VS
ConstraintFeeding network structural complexity

Inspiration 1 : Cross-domain reference

Application Principle: #6 Universality (Multi-functionality)
Cross-domain applicability Assess applicability
X-ray inspection using wavelength-shifting fiber-coupled scintillation detectors
Innovative Solution Refine solution

Dual-function tapered slot feed with integrated impedance transformation

Tapered slot feed merges matching and radiation functions
How to solve :
  • Replace conventional microstrip feed with exponential tapered slot transition (Vivaldi-type) that simultaneously performs 50Ω impedance transformation and bandwidth enhancement across 24-40 GHz, eliminating separate multi-stage quarter-wave transformers
  • Design slot taper with opening rate parameter C=0.15-0.25 mm⁻¹ and total length 4-6 mm to achieve >15% impedance bandwidth (VSWR<2) while maintaining <λ/2 footprint, fabricated on standard Rogers RO4003C substrate (εr=3.55, tanδ=0.0027) using single-layer photolithography with ±10 μm tolerance
  • Integrate resistive loading strips (100-200 Ω/square thin-film resistor) along slot edges to suppress higher-order modes and flatten impedance response, ensuring reflection coefficient <-15 dB across entire 5G NR n257/n258/n260 bands without additional tuning networks
Expected Effect : Bandwidth >15% (3.6-6 GHz at 24-40 GHz), feeding complexity reduced 60% vs multi-stage transformers, insertion loss <0.4 dB
Risk Control :
  • slot taper fabrication precision ±10 μm
  • resistive film uniformity control
  • substrate dielectric tolerance impact

Problem Direction 3 :

ImproveRadiation performance stability
VS
ConstraintFeeding network structural complexity

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Sensor devices with liquid-filled cavity and air cavity
Innovative Solution Refine solution

Frequency-adaptive liquid dielectric patch antenna for stable 5G NR radiation

Liquid dielectric stabilizes impedance across band
How to solve :
  • Replace solid substrate with liquid dielectric cavity (deionized water-glycerol mixture, εr=15–25, tan δ<0.02) beneath patch — viscosity adjusts resonance damping to flatten frequency response across 24–40 GHz
  • Seal liquid in 0.6mm PTFE enclosure with flexible membrane top surface — patch printed on membrane deforms slightly with frequency, auto-compensating impedance mismatch without multi-stage transformers
  • Integrate microfluidic temperature control (±0.5°C stability
Patsnap Eureka Solution