DFMA driven manufacturing plan for a phase-locked dielectric resonator oscillator

Abstract

This thesis studies how Design for Manufacture and Assembly (DFMA) and triangulation can improve the mechanical assembly of a phase-locked 8 GHz dielectric oscillator, that is utilized in advanced communication systems like radars and satellites. The devices dielectric resonator oscillator (DRO) works by electromagnetic waves being introduced by an input signal, that are then confined within a cavity and are allowed to oscillate. A phase-locking circuit is used to achieve high phase noise minimization, which works by using a circuit to lock the signal generated by the DRO to a low phase noise frequency. The high phase noise minimization specifically makes the device suitable the application. The research provides a validated manufacturing plan together with a systematic material selection and DFMA analysis. The manufacturability and assembility is ensured by machining instructions communicated with ISO 2768-mK and Geometric Dimensioning and Tolerancing (GD&T) technical documentation. The primary function of the devices housing is to protect the electrical components within from electromagnetic interference, that would harm the resonant frequency. As the goal of the research is to provide a means to manufacture and to ensure the devices performance, the two metrics for measuring manufacturability and shielding capacity are determined to be conductivity (milli Siemens per meter) and hardness (Brinell hardness). The metrics are used in evaluating the material within the 6000 series for aluminium alloys, where aluminium alloy 6061 (AA-6061-T6) is typically used for the applications. Aluminium alloy 6101 (AA-6101-H111) is chosen as it has the most ideal combination of the two metrics. When milling, drilling and threading the aluminium housing unit, the total machining time is simulated to be 9 minutes and 25 seconds excluding tool changing times. An alternative manufacturing method consideration to the traditional milling and drilling used for the suggested alloy (AA-6101), is severe plastic deformation (SPD) additive manufacturing, which offered a strength increase of 2.5 higher than the established process. The research weighs the benefits of material choices and manufacturing methods to provide a highly manufacturable and high performing phase-locked dielectric resonator oscillator.