【正文】 switch contact is imported from Pro/E into ANSYS – The model is then broken into small elements with the mesh tool for analysis – The material properties are entered for the desired material 3D Mechanical Analysis (ANSYS) The contact is then constrained and a force is applied to the contact point to determine the spring performance and resultant stresses 3D Mechanical Analysis (ANSYS) RF Simulation Capability ? ANSOFT 3D High Frequency Structure Simulator ? Model any Geometry ? No Frequency Limitation ? S Parameter Analysis – Return Loss, VSWR, Insertion Loss etc. ? Radiated Power ? E Field Plots ? Time Domain Analysis ? Optimization Capability RF Simulation Capability ? The connector is designed using standard RF practices and 2D linear analysis programs for “ballpark” performance – Calculate impedances within the connector – Calculate nominal pensation steps within the connector ? Draw the problem in HFSSimport from PROE: IGES (3D), or DXF (2D)File ? Assign the materials ? Set the ports and boundary conditions (symmetry) ? Solve ? Analyze frequency and time domain plots RF Simulation Capability ? Draw the RF Model from the Mechanical drawing and assign material ? Set boundary conditions and ports RF Simulation Capability ? Plot the desired S Parameters ? Solve the problem based on the mesh structure RF Simulation Capability ? View Time Domain response to determine the location of impedance mismatch RF Simulation Capability ? All design changes are made on the puter (No samples made until the design is optimized) ? Simulations in a matter of minutes, or hours at most ? Numerous iterations in a matter of hours or days ? Final modifications (if needed) made after testing HFSS Example – SMT Connector on Microstrip ? Connector has excellent Return Loss (35 to 40 dB) ? When mounted on board, performance deteriorates (20 dB) due to the mismatch at the launch Customer must supply board characteristics: ? Thickness ? Trace width ? Material (dielectric constant) ? Transmission line type (.. Microstrip, strip line) Mismatch Initial simulation results Return Loss Insertion Loss HFSS Example – SMT Connector on Microstrip HFSS Example – SMT Connector on Microstrip .010 wide .015 wide .022 wide Modify launch area to reduce the negative (capacitive) discontinuity at the launch area TDR Result Capacitance due to launch HFSS Example – SMT Connector on Microstrip ? Able to achieve a significant improvement in Return Loss and Insertion Loss by modifying the launch area Return Loss Insertion Loss Final Return Loss Final Insertion Loss Contact too close to body 5 mm Diameter too small (35 ohm impedance) ANSOFT HFSS Model Initial VSWR HFSS Example – R/A Plug for LMR400 Remended Design Changes: ? Remove Chamfer at solder post on contact ? Increase 5mm diameter to mm diameter on Body ANSOFT Model Increase diameter to mm Remove chamfer and shorten contact by mm Final improved VSWR HFSS Example – R/A Plug for LMR400 Test CapabilityS Parameters ? Stateoftheart Network Analyzers ? HP 8510: Ghz Vector Network Analyzer ? HP 8753D: 50 Ohm 6 Ghz Vector Network Analyzer ? HP 8753D: 75 Ohm 3 Ghz Vector Network Analyzer – Return Loss – Insertion Loss – VSWR – Crosstalk – RF Leakage RF Leakage Test chamber Test CapabilityS Parameters ? There are no “high tech” puter programs to predict IMD performance ? Devices must be built and tested ? Stateoftheart measurement test set using 20 watt (+43 dBm) signals with a system noise floor of 130 to 135 dBm ? Computer Automated inhouse programming capabilities to customize test measurements ? Typical specifications of –116 to –120 dBm for 716 and Type N connectors on helical and annular cables Test Capability PIM Test Capability PIM Test Capability PIM Computer Control (HP VEE Interface) ? Select a connector based on the information learned from asking questions about the 10 RF parameters: ? 1. Impedance Typical impedance of a system is 50 or 75 ohm. See Overview in catalog for impedance by series. ? 2. Frequency Range Connector series range from 100 MHz to GHz. See Overview in catalog for frequency range by series. ? 3. Cable Type Connector series are designed to terminate to a limited number of cable types. Is it a new cable required by the customer? Is it a PC style? See the “Cable Selection Chart” in the catalog. ? 4. Electrical/Mechanical requirements VSWR, Voltage Rating, Temperature Range, and other environmental requirements are all key specifications. ? 5. Coupling Type Choose between Threaded, Bayo, Snapon, and Pushpull based on all of the above. Connector Selection ? Coupling style – Frequency range: 6 Ghz – Power Handling: 5 Watts Average – RF Leakage: 70 dB (Eliminates Push on or Bayo styles) – PIM requirements: None ? Connector style – Impedance: 50 Ohms – Return Loss: 20 dB – Insertion Loss: dB – Mechanical Restrictions – Available Real Estate: .5 “ long – Cable: RG142 ? Cost, other mechanical requirements, etc. N, TNC, SMA, 716 SMA, TNC Final Connector Choice Connector Selection Amphenol174。 RF Global RF Solutions