Phased Array Front-End Architecture & Simulation Engineer (D2D + Broadband, Tx/Rx)
Location: San Diego, CARole 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 definitiongain staging, power budget, NF allocation, linearity allocationPA specification derivation
- Psat, P1dB, PAE, OIP3 targets from system EIRP/ACLR requirementsLNA specification derivationNF, gain, IP3, stability margin targets from system G/T and interference requirements
- Architecture partitioningfront-end vs. beamformer boundary, IF vs. RF beamforming implications on front-end
- Multi-temperature architecture marginperformance 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 deratingDPD architecture verificationLUT, GMP, convergence performance, coefficient stabilityET/APTsupply modulator modeling, efficiency vs. linearity tradeoffsOOBEspectral regrowth, ACLR/ACPR, spectral mask compliance (3GPP NTN, ITU)
Tx array performance: beam-dependent EIRP, active element patterns, scan loss, cross-factor
Receive Chain ModelingLNA noise modeling: NF vs. frequency/temperature/bias, noise parameters (NFmin, Gopt, Rn)NF cascademulti-stage noise figure, gain distribution, system noise temperature
Receiver sensitivity: MDS, SNR budget from antenna to ADCInterference 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 & Compliance3GPP NR NTN emission masks, ITU RR Article 22 EPFD limits
Co-existence analysis, sensitivity/selectivity requirements
Software Skills RequiredMATLAB/SimulinkPA/LNA behavioral modeling, DPD algorithm simulation, Tx/Rx link budget tools, array performance Monte Carlo, architecture trade study frameworks
PythonSignal processing, batch simulation automation, data pipeline, trade study scripting
Keysight ADSHarmonic balance, X-parameter models, load-pull simulation, noise analysis, circuit-level architecture validation3GPP waveform toolsOFDM/SC-FDMA, ACLR/EVM, spectral mask verificationNOT Required for This Role
Antenna element EM design (HFSS, CST)PCB layout tools (Allegro, Altium)FPGA/RTL design
Mechanical CADManufacturing/NPI/yield
Package physical design
Qualifications:- RequiredMS 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 3GPP NR or satellite communication standards
- PreferredMulti-band architecture experience (cellular frequencies + Ka-band)DPD/APT architecture definition and simulationNTN or satellite direct-to-device system experience
- Experience correlating architectural predictions with measured hardware data
- DeliverablesFront-end architecture specification (Tx and Rx) for D2D and broadband KaPA/LNA behavioral model library for architectural verification
- Architecture trade study reports with performance predictions
- Simulation-based verification that architecture meets system requirementsDPD/APT architecture recommendation with supporting analysis
- Component specification documents derived from system requirements
