Disertasi ini membincangkan kaedah merekabentuk Penukarturun 18GHz di mana ia adalah kombinasi daripada penguat bisingan rendah, pencampur, pengganda dan pengayun kawalan voltan (VCO). Frekuensi 18 GHz berada di antara jalur K dan jalur Ku iaitu 12- 18 GHz dan 18-26.5 GHz masing-masing. Penukarturun ini direkabentuk untuk aplikasi sistem tanpa wayar. Dalam merekabentuk penukarturun ini, pengganda perlu direkabentuk. Kesan teknik pematerian yang digunakan pada pengganda terhadap penukarturun diperhatikan. Teknik pateri topeng digunakan. Pengayun tempatan juga perlu disediakan supaya isyarat LO yang dikehendaki boleh dicapai. Julat kuasa Penukarturun 18 GHz dengan kombinasi beberapa komponen termasuk pengganda yang direkodkan ialah dari -47.5 dBm ke -45 dBm. Frekuensi keluaran bagi penukarturun ini ialah 1GHz jika 18 GHz masukan diberikan. Beberapa ciri seperti gandaan penukaran, mampatan gandaan dan pemintasan tahap ketiga juga dilakukan. Pemintasan tahap ketiga hanya dialkukan menggunakan simulasi disebabkan peralatan yang terhad.
_________________________________________________________________________________________
This dissertation presents an approach of designing 18 GHz Downconverter which is the combination of a low noise amplifier, mixer, multiplier and voltage contol oscillator (VCO). The 18 GHz frequency falls between the K band and Ku band which is 12-18 GHz and 18-26.5 GHz respectively. The downconverter is designed to intend the operation at 18 GHz and convert it to 1 GHz. The downconverter is designed for the application in the wireless systems. In designing the downconverter, a PCB for a multiplier needs to be designed. The effects of the soldering techique to used for the multiplier to the downcnverter is observed. Solder mask technique is carried out. The correct local oscillator also has to be provided in order to get the desired LO signal. The range of the power of the 18 GHz Downconverter with the combination of several modules including the multiplier recorded is from -47.5 dBm to -45 dBm. The output frequency of the downconverter is 1 GHz if 18 GHz input is supplied. Some characteristics such as the conversion gain, gain compression and third order intercept is also done. The third order intercept is only done using simulation because of the limitation of the equipment.
18 ghz downconverter design_Razed Hariz bin Ahmad_E3_2011_875004024_00003089580_NI