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Multi-Resonating UWB Printed Monopole Antenna

MetadataDetails
Publication Date2019-11-02
JournalInternational Journal of Recent Technology and Engineering (IJRTE)
AuthorsSingh Sanjay
InstitutionsAditya Birla (India)
Citations1
AnalysisFull AI Review Included

Technical Documentation and Analysis: UWB Monopole Antenna Substrates

Section titled “Technical Documentation and Analysis: UWB Monopole Antenna Substrates”

This document analyzes the design requirements of a Multi-Resonating Ultra-Wideband (UWB) Printed Monopole Antenna (MPMA) developed on a low-cost FR4 substrate. While the successful deployment on FR4 validates the dual-resonator design methodology, 6CCVD identifies critical limitations in scalability and power handling that necessitate a transition to high-purity MPCVD diamond.

  • Core Achievement: The antenna configuration (Annular Ring + Diamond Patch) achieved a massive impedance bandwidth ratio of >7.85:1, covering 1.4 GHz to 11 GHz.
  • Performance Metrics: Demonstrated high efficiency (80% to 95%) and maximum gain between 2 dBi and 7 dBi across the entire UWB range.
  • Substrate Limitation: The utilized FR4 substrate (loss tangent $\delta$ = 0.01) imposes significant limitations on power integration, thermal management, and efficiency at higher mmWave frequencies (e.g., future 5G/6G or high-power satellite applications).
  • 6CCVD Value Proposition: Replicating this design on 6CCVD’s Ultra-Low Loss Polycrystalline Diamond (PCD) or High-Purity Single Crystal Diamond (SCD) substrates would dramatically reduce dielectric loss, improve power handling, and ensure efficiency stability well beyond the 11 GHz range.
  • Custom Manufacturing: 6CCVD offers the large-area substrates (up to 125 mm) and high-precision laser machining required to implement the complex annular and diamond geometry onto diamond wafers.

The following table summarizes the critical performance parameters and geometric specifications of the UWB MPMA detailed in the research paper.

ParameterValueUnitContext
Frequency Bandwidth ($S_{11}$ < -9.6 dB)1.4 - 11.0GHzUltra-Wideband (UWB) operation
Impedance Bandwidth Ratio> 7.85:1N/AHigh bandwidth performance
Radiation Efficiency80 - 95PercentageAcross entire 1.4 GHz to 11 GHz range
Maximum Gain2 - 7dBiAcross entire 1.4 GHz to 11 GHz range
Substrate Relative Permittivity ($\epsilon_{r}$)4.3N/ABaseline FR4 material
Substrate Loss Tangent (tan $\delta$)0.01N/ADielectric loss metric for FR4
Substrate Thickness ($h$)1.59mmStandard printed circuit thickness
Total Antenna Footprint80 x 80mmPhysical dimension on FR4
Partial Ground Plane Dimension80 x 10mmDefines matching network behavior
Annular Ring Outer Radius ($R_{1}$)25mmLow-frequency resonator size
Annular Ring Inner Radius ($R_{2}$)23mmDefines 2 mm ring width
Microstrip Feed Gap ($p$)0.5mmOptimized for impedance matching

The UWB performance of the MPMA was achieved through specific design methodologies focusing on impedance matching and multi-resonance excitation.

  1. Dual-Resonator Design: The antenna integrates two distinct radiating elements to excite multiple modes and widen the operational bandwidth:
    • The Annular Ring primarily drives resonance at the lower frequency band.
    • The Diamond Shaped Patch is incorporated within the ring to excite higher-order modes, necessary for ultra-wideband coverage.
  2. Substrate Selection: Low-cost FR4 ($\epsilon_{r}$ = 4.3, tan $\delta$ = 0.01, $h$ = 1.59 mm) was chosen for prototyping, setting the initial physical dimensions.
  3. Impedance Matching Network: A microstrip line feed, along with a partial ground plane (80 mm x 10 mm), acts as a quarter-wavelength transformer to ensure efficient power transfer to the radiating patches.
  4. Parameter Optimization: Critical geometric dimensions (radii $R_{1}$, $R_{2}$; diamond diagonals; feed gap $p$) were systematically optimized using IE3D simulation software to achieve the $S_{11}$ < -9.6 dB requirement across the 1.4 GHz to 11 GHz span.
  5. Prototyping and Validation: The optimized design was fabricated, and simulated results were validated against laboratory measurements, confirming omni-directional pattern and stable high efficiency (80%-95%).

This research demonstrates a robust design template for UWB antennas. To extend this technology into high-power RF systems, integrated semiconductor devices, or high-frequency mmWave applications, the intrinsic limitations of the FR4 substrate (high loss, poor thermal properties) must be overcome using MPCVD Diamond.

Research Requirement/Limitation6CCVD Material/CapabilityAdvantage for UWB Replication
Dielectric Loss Limitation: FR4 tan $\delta$ (0.01) creates inherent losses, especially as frequencies approach 11 GHz and beyond.Optical Grade SCD/PCD: Diamond tan $\delta$ < 10-4 (up to 100x lower than FR4).Enables truly lossless integration and maintains extreme efficiency for UWB signals well into the mmWave spectrum (5G/6G).
Thermal Dissipation: FR4 is inadequate for embedding high-power amplifiers or switches necessary for active UWB arrays.High Purity MPCVD Substrates: Thermal conductivity up to 2000 W/m¡K.Provides unmatched thermal heat spreading and ensures frequency stability by preventing thermal drift in embedded systems.
Geometry and Size: Requires complex geometries (annular ring, diamond) on substrate sizes up to 80 mm x 80 mm.Custom Laser Machining & Large Area PCD: Wafers up to 125 mm (PCD) available; precision laser cutting ensures complex geometry alignment (e.g., 0.5 mm feed gaps).Allows for direct scaling and high-tolerance replication of the UWB design on diamond platforms.
Interconnection & Matching: Requires precise microstrip lines and robust feed structure.In-House Metalization: 6CCVD offers internal deposition of high-conductivity metal stacks (Ti/Pt/Au, Ti/W/Cu).Critical for creating stable, low-resistance microstrip transmission lines and robust ohmic contacts necessary for diamond RF circuits.

To replicate and extend this UWB research for applications demanding minimal loss and maximum power efficiency, 6CCVD recommends:

  • Optical Grade Single Crystal Diamond (SCD): For applications requiring the absolute lowest loss characteristics and highest thermal performance in smaller formats (up to 10 mm substrates).
  • Ultra-Low Loss Polycrystalline Diamond (PCD): Ideal for larger dimension antennas (up to 125 mm wafers) and cost-effective prototyping where extreme low loss (Ra < 5nm polishing) is still paramount.

6CCVD’s in-house PhD team specializes in translating conventional RF and microwave designs onto diamond substrates. We offer engineering consultation to assist with material selection, optimizing dielectric loading ($\epsilon_{r}$ changes when moving from FR4 to Diamond), and ensuring proper thermal and electrical integration for UWB antenna array and embedded system projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The multi-resonating, Annular Ring with Diamond Patch UWB Antenna has been presented, that produces large bandwidth. This configuration shows the bandwidth for VSWR = 2, or for corresponding S11 of 1.4GHz - 11 GHz, which includes UWB. This proposed configuration shows, approximately, Omni-directional radiation pattern on azimuthal plane for the entire range of frequency band. The measured and simulated results are shown; they promise for agreeable similarity. The impedance bandwidth ratio for presented antenna is achieved better than 7.85: 1 for S11< -9.6 dB. This antenna combines two resonators, i.e. annular ring and diamond shaped patch, within FR4 substrate of dimension 80mm x 80mm. This low profile compact antenna can be very useful for many embedded systems.