Phased Array Frontend Engineer, Architecture & Simulation

Phased Array Front-End Architecture & Simulation Engineer (D2D + Broadband, Tx/Rx)

Location:

San Diego, CA

Role Summary

Architect and simulate phased array front-end performance for both D2D and broadband Ka-band satellite payloads. Define front-end architecture (Tx and Rx chains), build predictive models to verify architectural choices, and confirm system requirements are met through simulation-based verification.

Responsibilities

• Define front-end architecture:
  Tx/Rx chain topology, component partitioning, gain/power/NF distribution, PA/LNA placement and specification
• Verify architecture meets system-level requirements through simulation: EIRP, G/T, OOBE, sensitivity, dynamic range
• Build and maintain PA and LNA behavioral models to predict array-level performance
• Validate DPD/APT architectural decisions through closed-loop simulation
• Perform architecture trade studies: efficiency vs. linearity, noise vs. gain distribution, single-vs-multi-stage, back-off allocation
• Support hardware verification by correlating measured component data to architectural models

Hardware Knowledge Required

Front-End Architecture

• Tx/Rx chain architecture definition: gain staging, power budget, NF allocation, linearity allocation
• PA specification derivation:
  Psat, P1dB, PAE, OIP3 targets from system EIRP/ACLR requirements
• LNA specification derivation: NF, gain, IP3, stability margin targets from system G/T and interference requirements
• Architecture partitioning: front-end vs. beam former boundary, IF vs. RF beamforming implications on front-end
• Multi-temperature architecture margin: performance budgets at 25°C/50°C/85°C corner cases

Transmit Chain Modeling

• Nonlinear PA behavioral models (Volterra, memory polynomial, Rapp, Saleh), AM-AM/AM-PM, thermal derating
• DPD architecture verification: LUT, GMP, convergence performance, coefficient stability
• ET/APT: supply modulator modeling, efficiency vs. linearity tradeoffs
• OOBE: spectral regrowth, ACLR/ACPR, spectral mask compliance (3
  
  GPP NTN, ITU)
• Tx array performance: beam-dependent EIRP, active element patterns, scan loss, cross-factor

Receive Chain Modeling

• LNA noise modeling: NF vs. frequency/temperature/bias, noise parameters (NFmin, Γopt, Rn)
• NF cascade: multi-stage noise figure, gain distribution, system noise temperature
• Receiver sensitivity: MDS, SNR budget from antenna to ADC
• Interference tolerance: blocker desensitization, IMD3/IMD5, receiver intermodulation
• Rx array performance: G/T, beam-dependent sensitivity, noise correlation

Array-Level Architecture Verification

• Active element patterns, mutual coupling, scan loss, grating lobe analysis
• Beamforming: beam weight application, quantization effects, multi-beam interference
• Cross-pol and cross-factor: inter-element coupling, polarization purity vs. scan
• Architectural verification: confirming component specs roll up to meet system performance

Regulatory & Compliance

• 3
  
  GPP  emission masks, ITU RR Article 22 EPFD limits
• Co-existence analysis, sensitivity/selectivity requirements

Software Skills Required

• MATLAB/Simulink: PA/LNA behavioral modeling, DPD algorithm simulation, Tx/Rx link budget tools, array performance Monte Carlo, architecture trade study frameworks
• Python:
  Signal processing, batch simulation automation, data pipeline, trade study scripting
• Keysight ADS:
  Harmonic balance, X-parameter models, load-pull simulation, noise analysis, circuit-level architecture validation
• 3
  
  GPP waveform tools: OFDM/SC-FDMA, ACLR/EVM, spectral mask verification

NOT Required for This Role

• Antenna element EM design (HFSS, CST)
• PCB layout tools (Allegro, Altium)
• FPGA/RTL design
• Mechanical CAD
• Manufacturing/NPI/yield
• Package physical design

Qualifications

Required

• MS or PhD in EE (RF, Communications, or Signal Processing)
• 5+ years RF front-end architecture and simulation experience
• Expert MATLAB/Simulink user for behavioral modeling and system simulation
• Experience defining PA/LNA specifications from system requirements
• Tx and Rx chain analysis (OOBE/ACLR + NF/sensitivity)
• Phased array front-end architectural tradeoff experience
• Familiarity with 3
  
  GPP  satellite communication standards

Preferred

• Multi-band architecture experience (cellular frequencies + Ka-band)
• DPD/APT architecture definition and simulation
• NTN or satellite direct-to-device system experience
• Experience correlating architectural predictions with measured hardware data

Deliverables