Miniaturised multilayer RF and microwave Circuits

Nassar, Shamim Omar (2016-03)

Thesis (D.Phil)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: Ceramic and laminate multilayered technologies are explored in the design of novel circuit topologies and in novel implementations of classical circuit topologies. A cross-slot coupled filter topology implemented in folded substrate integrated waveguide (FSIW) is proposed and is shown to exhibit properties that make it favourable for diplexer design. A C-Band diplexer design is presented. The diplexer is fabricated in both Liquid crystalline Polymer (LCP) and Printed Circuit Board (PCB) multilayed technology. The viability of both processes for this type of circuit is analysed and performance is verified by simulation and measurement. A ’ridge-like’ folded substrate integrated waveguide resonator is proposed. A comparative analysis of this resonator and a traditional ridge waveguide resonator structure in substrate integrated technology is presented. For rectangular waveguide resonators with identical outer dimensions, the former is shown to achieve lower operational frequencies relative to the latter. Two X-band filters are designed using the ’ridge-like’ FSIW resonator. Both filters are fabricated in PCB multilayered technology and performance is verified by both simulation and measurement. The measurement results of the first, a second order filter, show a maximum insertion loss of 2.23 dB for the primary band and a wide frequency range of 7.5 GHz between the first passband and the second. The second filter is a fourth order filter which achieves a maximum measured insertion loss of 4.7 dB for the primary passband with the second passband occuring over 8.5 GHz away. A classical sequence asymmetric RC polyphase filter (PPF) is implemented in low temperature co-fired ceramics (LTCC) technology. The novel implementation realises a miniaturised structure comprising embedded components interconnected using planar transmission lines. Verification of the structure’s performance is by simulation of a three segment PPF. The LTCC PPF is shown to achieve an image suppression of 35 dB over a frequency range of 100 MHz to 300 MHz and a gain error of 0.14dB between its quadrature outputs. The final design is a novel implementation of a miniaturised two-stage PIN Diode limiter-switch in LTCC. The structure comprises both embedded components and surface mount components interconnected using planar transmission lines and vias. Circuit viability is assessed through simulation of a multilayered L-Band limiter-switch design. An insertion loss of 0.25 dB and a return loss of 25.34 dB at a center frequency of 1.3 GHz are obtained when the switch is in its off-state. When a large 1 ms input pulse signal of 45 dBm is applied at the input of the limiter-switch, the resulting output pulse has a flat leakage of approximately 16.4 dBm.

AFRIKAANSE OPSOMMING: Keramiese en gelamineerde tegnologieë word in hierdie werk ondersoek vir die ontwerp van nuwe stroombaantopologieë en nuwe implementerings van klassieke stroombaantopologieë. ‘n Gekruisde gleuf filter topologie, geïmplementeer in Gevoude Substraat Geïntegreerde Golfleier, word voorgestel. Dit word aangetoon dat hierdie topologie eienskappe besit wat dit nuttig maak vir gebruik in diplekser ontwerp, en ‘n C-band diplekser word ontwerp. Die ontwerp word in beide Vloeibare Kristalyne Polimeer tegnologie en gedrukte stroombaanbord tegnologie implementeer, en die geskiktheid van hierdie tegnologieë word bespreek. Die werkverrigting van die ontwerpe word met simulasie en metings geverifieer. ‘n Rif Gevoude Substraat Geïntegreerde Golfleier resoneerder word voorgestel. ‘n Vergelykende studie van hierdie resoneerder en ‘n tradisionele Rif Golfleier resoneerder in Substraat Geïntegreerde Golfleier word gedoen. Vir reghoekige golfleier resoneerders met identiese buite-afmetings, word getoon dat eersgenoemde laer gebruiksfrekwensies toon . Twee X-band filters word ontwerp met die nuwe resoneerder. Beide filters word vervaardig in multilaag stroombaanbord tegnologie, met die werkverrigting geverifieer met metings en simulasie. ‘n Tweede-orde filter wys ‘n maksimum insetverlies van 2.23 dB vir die primêre band, en ‘n 7.5 GHz stopband tussen die eerste en tweede deurlaatband. ‘n Vierde-orde filter toon ‘n insetverlies van 4.7 dB vir die primêre deurlaatband, en ‘n 8.5 GHz stopband. ‘n Klassieke asimmetriese RC-polifase filter word geïmplementeer in Lae Temperatuur Ko-gevuurde Keramiek tegnologie. Die nuwe implementering realiseer ‘n miniatuur struktuur bestaande uit ingeslote komponente, verbind met planêre transmissielyne. Verifikasie van die struktuur word gedoen deur middel van ‘n drie-segment polifase filter, met ‘n beeldverwerping van 35 dB oor die 100 MHz tot 300 MHz band, en ‘n aanwinsfout van kleiner as 0.14 dB tussen die kwadratuur uitreespannings. Die finale ontwerp is ‘n implementering van ‘n geminiaturiseerde twee-stadium PIN diode beperker in Lae Temperatuur Ko-gevuurde Keramiek tegnologie. Die struktuur bestaan uit beide ingeslote en oppervlak-gemonteerde komponente, wat verbind word met planêre transmissielyne en vias. ‘n L-band beperker word ontwerp en met simulasie geverifieer. ‘n Insetverlies van 0.25 dB en ‘n weerkaatskoëffisiënt van 25 dB by 1.3 GHz word behaal in die af-toestand. Met’n groot 1 mikrosekonde intreepuls van 45 dBm wat aangelê word by die intree, word ‘n uittree verkry met ‘n plat pulsvorm van 16.4 dBm.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98484
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