Manufacturing feasibility assessment
5. Verdict
A single LPDA is directional, so use a switched or multi-element omnidirectional array, then validate radar band, power, EMC and defence qualification with a 5-unit RF prototype.
6. Subsystems
- 6.1 RF architecture and coverage definitionHIGH
- 6.2 LPDA radiating structureMEDIUM
- 6.3 Feed, balun and RF interconnectMEDIUM
- 6.4 Environmental enclosure and radomeMEDIUM
- 6.5 Mechanical mounting and alignmentMEDIUM
- 6.6 Production test and calibrationMEDIUM
- 6.7 Defence qualification packageHIGH
7. Bill of materials
| Item | 100 | 1,000 | 10,000 |
|---|---|---|---|
| 7.1 Aluminium boom, LPDA elements and insulated supports | ₹8,000–15,000 | ₹4,500–9,000 | ₹2,500–5,000 |
| 7.2 RF feed, balun / transformer and controlled-impedance harness | ₹7,000–16,000 | ₹4,000–9,000 | ₹2,000–6,000 |
| 7.3 RF connector, gland and low-loss pigtail | ₹2,000–7,000 | ₹1,200–4,000 | ₹800–2,000 |
| 7.4 UV-stable radome or RF-transparent protective cover | ₹5,000–15,000 | ₹3,000–8,000 | ₹1,500–4,000 |
| 7.5 Mounting bracket, clamps and stainless fasteners | ₹4,000–12,000 | ₹2,000–6,000 | ₹1,000–3,000 |
| 7.6 Seals, grounding hardware and corrosion-protection finish | ₹2,000–5,000 | ₹1,000–3,000 | ₹600–1,500 |
| 7.7 Assembly, VNA test, burn-in and inspection | ₹5,000–11,000 | ₹3,000–7,000 | ₹2,000–5,000 |
At 100 units this adds roughly ₹30,000–80,000/unit; at 1,000, ₹3,000–8,000/unit; at 10,000, ₹300–800/unit. At 10,000 units, estimated BOM remains below ₹26,500, under 40% of the ₹1,50,000 entry retail target, assuming a single-sector 1–6 GHz, up-to-200 W CW design.
8. Gates to clear
8.1 [DFM]
“Omni LPDA” is not a single-antenna geometry: an LPDA is directional. Frequency range, gain, polarization, power, coverage and radome loss are also undefined.
Path: Convert the requirement to either a specified directional LPDA or a 3–4 sector LPDA array with corporate-feed/switching network. Freeze band, gain, azimuth coverage, polarization, CW/peak power, wind load and IP target before RF and tooling release.
8.2 [Certification]
A passive antenna normally has no standalone BIS or WPC ETA route, but the radar transmitter/system requires applicable WPC/DoT spectrum authorization. Defence contracts may require DGQA acceptance and MIL-STD-461/810 evidence.
Path: Obtain the operating-band and user authorization route from the defence customer and WPC/DoT interface. Run RF, ingress, salt-fog, vibration and thermal testing through an NABL-accredited lab; execute DGQA first-article inspection and MIL-STD-461/810 testing where the procurement specification calls for it.
8.3 [Tooling]
Dedicated radome and element-forming tooling is uneconomic before the coverage architecture and annual demand are committed; a sector array multiplies antenna count and RF-feed cost.
Path: Build 10–25 CNC/fixture-made engineering units first, then use low-volume composite radomes for field trials. Release matched metal-forming and compression-mould tooling only after first-article approval and a committed 1,000-unit or higher call-off.
9. Prototype sequence
- 9.1Issue a requirements freeze covering radar band, gain, polarization, azimuth coverage, power, duty cycle, environment, mounting and qualification standard.This resolves the directional-versus-omni conflict and prevents an invalid antenna geometry from entering design.
- 9.2Model directional and 3–4 sector options in EM simulation, including radome, mast, feed network and mutual coupling.It establishes achievable gain, coverage ripple, nulls, power handling and mechanical envelope before fabrication.
- 9.3Build 3–5 CNC-fabricated RF prototypes with interchangeable feed and radome configurations.This allows rapid VNA, power and pattern correlation without committing hard tooling.
- 9.4Validate impedance, gain, azimuth coverage, cross-polarisation, power handling and environmental sealing at an accredited RF test facility.Measured performance must correlate with simulation before field deployment or qualification spending.
- 9.5Run a customer field trial, freeze the selected architecture, then complete first-article qualification and production-fixture validation.The required change is confirmed in operational use before radome and forming-tool investment.
Assessment criteria: J. Tanikella · Engine: GPT-5.6 Terra.
