ABSTRAKSI: Filter merupakan suatu perangkat untuk melewatkan frekuensi tertentu dengan meloloskan frekuensi yang diinginkan dan meredam frekuensi yang tidak diinginkan. Frekuensi yang digunakan akan berbeda-beda tergantung dengan aplikasi yang digunakan. Berdasarkan daerah frekuensi yang dilewatkan, filter dibagi menjadi beberapa jenis yaitu: LPF (Low Pass Filter), BPF (Band Pass Filter), HPF (High Pass Filter), dan BSF (Band Stop Filter)
Pada proyek akhir ini direalisasikan Band Pass Filter (BPF) pada frekuensi 1930- 1990 MHz untuk aplikasi WCDMA dengan filter Equal Ripple (Chebyshev). Frekuensi tersebut adalah frekuensi downlink dari BTS ke mobile station. Filter berupa BPF hairpin yang merupakan salah satu metode perancangan filter elemen terdistribusi dengan panjang resonator λg/2 yang terkopel secara paralel dan mempunyai topologi resonator seperti huruf ‘U’. Perealisasian filter menggunakan mikrostrip berbahan Rogers Duroid 4003c sebagai saluran transmisinya.
Informasi kinerja filter diukur dengan menggunakan Network Analyzer. Beberapa parameter yang diukur dalam perancangan BPF ini adalah respon frekuensi filter, bandwidth, insertion loss, return loss, VSWR (voltage standing wave ratio), dan impedansi terminal. Adapun hasil pengukuran dari karakteristik BPF ini adalah frekuensi tengah 1926 MHz dengan bandwidth 62 MHz, insertion loss 9.471 dB, return loss 1.709 dB (input) dan 9.567 dB (output), VSWR 1.5028 (input) dan 1.4924 (output), impedansi terminal 34.509 + j56.674 (input) dan 31.147 + j6.568 (output).Kata Kunci : bandpass filter, microstrip, bandpass filter hairpin, chebyshev, wcdmaABSTRACT: Filter is a device to pass a particular frequency by passing wanted frequency and reduce unwanted frequencies. The frequency that is used is depend on the applications used. Based on the frequency regions that are passed, the filter is divided into several types: LPF (Low Pass Filter), BPF (Band Pass Filter), HPF (High Pass Filter), and BSF (Band Stop Filter)
This final project was aimed to realized Band Pass Filter (BPF) at frequency 1930- 1990 MHz for WCDMA application with Equal Ripple filter (Chebyshev). That frequency is the downlink frequency of BTS to the mobile station. The filter is a hairpin filter, which is one method of designing a distributed element filter with λg / 2 length of resonators that is parallel coupled and have resonators topology as 'U' shape. Realization of this filters was using microstrip with Rogers Duroid 4003c material as a transmission channel.
The information filter performance was measured by using Network Analyzer. In this BPF designing and realizing, some of the parameters measured are frequency response, bandwidth, insertion loss, return loss, VSWR (voltage standing wave ratio), and terminal impedance. The results of BPF characteristics measurements are : center frequency is 1926 MHz with 62 MHz bandwidth, insertion loss 9.471 dB, return loss 1.709 dB (input) and 9.567 dB (output), VSWR 1.5028 (input) and 1.4924 (output), terminal impedance 34.509 + j56.674 (input) and 31.147 + j6.568 (output).Keyword: bandpass filter, microstrip, hairpin bandpass filters, chebyshev, wcdma