2 1 2 Transmission line 3 Antenna 4

2 목차 1. 무선 통신 시스템 2. Transmission line 3. Antenna 4. Filter 5. Amplifier 6. Oscillator 7. Modulation/Demodulation EMLAB

2. Transmission line 개요 10 i (z, t) i (z+ z, t) + L z v (z, t) - + v (z, t) z + C z v (z+ z, t) - z EMLAB

Transmission line eq. solution 11 EMLAB

Line길이에 따른 반사파 영향 13 Impedance mismatched + V - Vin R Vt. Pulse R 1 SRC 1 R=20 Ohm Vout MLIN R R 2 R=1 k Ohm + V - t Zs = 20 Z 0= 50 + V - Z 0= 50 ZL= 1 k + V - 0. 5 m + V - EMLAB

23 Image theory +q 1 - - Perfect electric conductor +q 1 Perfect electric conductor -q 1 Image charge EMLAB

25 Small monopole antennas 코일 없이 공진하려면 17 cm 이어야 하나 L성분 때문에 공진 가능함. Radiating element 50 mm 부분은 L의 역할 EMLAB

Inverted F antenna 26 Radiating E-field EMLAB

안테나 지향성 (Directivity) 27 Antenna gain = efficiency x directivity EMLAB

28 4. 필터 기초 가장 흔하게 쓰이는 coupled resonator filter 중심 주파수에서 공진하는 resonator EMLAB

공진 주파수 및 coupling 29 EMLAB

Dynamic range : lower limit 33 최소 입력 레벨은 증폭기의 Te (equivalent noise temperature에 의해 정해짐. ) Power output threshold 입력신호와 상관없이 회로 자체에서 생기는 noise로 인한 출력 EMLAB

Equivalent noise temperature of an amplifier 34 Figure 10 -5 (p. 491) Defining the equivalent noise temperature of a noisy amplifier. (a) Noisy amplifier. (b) Noiseless amplifier. EMLAB

36 Dynamic range : upper limit Dynamic range DC output Linear output Squared output EMLAB

Output signal from a non-ideal amplifier 40 입력 신호 출력 신호 Filter로 제거 가능 Filter로 제거 불가능 Filter로 제거 가능 EMLAB

43 6. Oscillator : Phase noise Control하기 힘듦. Phase nose 의 영향 1. SNR 이 나빠짐. 2. Selectivity가 나빠짐. EMLAB

44 Phase noise에 의한 SNR 악화 desired undesired EMLAB

Selectivity and phase noise spec. 45 S Selectivity EMLAB

46 GSM frequency bands There are fourteen bands defined in 3 GPP TS 45. 005, which succeeded 3 GPP TS 05. 05: GSM minimum spec. -23 d. Bm -33 d. Bm -43 d. Bm -99 d. Bm Frequency offset fm (MHz) Interfering signal level (d. Bm) Phase noise (d. Bc/Hz) 3. 0 -23 -138 1. 6 -33 -128 0. 6 -43 -118 System Band Uplink (MHz) Downlink (MHz) Channel number T-GSM-380 380. 2– 389. 8 390. 2– 399. 8 dynamic T-GSM-410 410. 2– 419. 8 420. 2– 429. 8 dynamic GSM-450 450. 4– 457. 6 460. 4– 467. 6 259– 293 GSM-480 478. 8– 486. 0 488. 8– 496. 0 306– 340 GSM-710 698. 0– 716. 0 728. 0– 746. 0 dynamic GSM-750 747. 0– 762. 0 777. 0– 792. 0 438– 511 T-GSM-810 806. 0– 821. 0 851. 0– 866. 0 dynamic GSM-850 824. 0– 849. 0 869. 0– 894. 0 128– 251 P-GSM-900 890. 0– 915. 0 935. 0– 960. 0 1– 124 E-GSM-900 880. 0– 915. 0 925. 0– 960. 0 975– 1023, 0124 R-GSM-900 876. 0– 915. 0 921. 0– 960. 0 955– 1023, 0124 T-GSM-900 870. 4– 876. 0 915. 4– 921. 0 dynamic DCS-1800 1710. 0– 1785. 0 1805. 0– 1880. 0 512– 885 PCS-1900 1850. 0– 1910. 0 1930. 0– 1990. 0 512– 810 EMLAB

47 7. 변조, 복조 Super-heterodyne receiver 두번에 걸쳐 down conversion하므로 낮은 Q 의 필터라도 문제없다. EMLAB

48 Direct conversion receiver 한번에 필터링해야 하므 로 높은 Q의 필터필요. • • • Very simple structure. Less costly than heterodyne receiver. Selectivity can be controlled with a simple low-pass filter. No image frequency. LO must have a high degree of precision and stability. EMLAB

49 Modulation schemes Baseband signal ASK Modulation 및 demodulation 방식에 따 라 BER이 다르다. Binary FSK Binary PSK EMLAB

ASK mod/demod 50 EMLAB

FSK mod/demod 51 EMLAB

PSK mod/demod 52 EMLAB

Error rate calc. for ASK synchronous demodulation 53 EMLAB

54 BER for ASK synchronous demodulation Gaussian 분포임. 필요한 BER로부터 SNR 추출 가능. EMLAB

55 BER for envelope detection Rayleigh 또는 Rician분포임. EMLAB

BER vs. demodulation scheme 56 EMLAB

57 Friis equation Antenna gain and effective area Received power : Radiation power density by a transmitting antenna Effective area of a receiving antenna EMLAB

58 Link analysis : Satellite DMB 日本 MBCO F 0 = 2642. 5 MHz BW = 25 MHz ANT EIRP: 67 d. BW Geostationary Orbit r = 35, 768 km Path loss Receiver Antenna gain : 0 d. Bi NF : x(2 d. B? ) (1) EIRP : 97 d. Bm (2) Path loss : 192 d. B (3) Received Isotropic power : -95 d. Bm ; (1)-(2) (4) Receiver antenna gain : 0 d. Bi (5) Received signal power : -95 d. Bm ; (3)+(4) (6) Thermal noise : -174 d. Bm /Hz (7) Received Pr/No : 79 d. B(Hz); (5)-(6) (8) Received C/No : 64. 2 d. B(Hz); (7)/ 30(채널 수) (9) Data rate : 54. 1 d. B (Hz) (256 kbps) (10) Received Eb/No : 10. 1 d. B ; (8)-(9) (11) Required C/No : 58 d. B(Hz) (ITU-R Bo. 1130 -4) (12) Required Eb/No : 3. 9 d. B (ITU-R Bo. 1130 -4); (11)-(9) (13) Receiver Noise Figure(x) + Margin : 6. 2 d. B EMLAB

Noise figure of a cascaded system 59 EMLAB

Intercept point of a cascaded system 60 EMLAB

RF block구성 예 1 62 AGC gain Zero IF (Direct conversion) LPF BW: 12. 5 MHz Analog Device AD 8347 Infineon BGA 612 Fc : 2642. 5 MHz BW : 25 MHz I+ Circular or linear pol. ANT LNA 1 AMP 1 Step attenuator IAMP 2 AGC 1/2 Agilent ATF 55143 유전체 필터 Fc: 2642. 5 MHz BW: 25 MHz Base band analog Hittite Q+ HMC 291 QGain: 69 B NF: 12 d. B • 전체 NF를 1. 5 d. B로 맞추 기 위해 IIP 3가 높은 LNA 를 전단에 두고 BPF를 그 뒤에 오게 함. Balun Toyocom VC-TCXO 13 MHz PLL setting RF PLL ADF 4113 Loop Filter LPF BW: 12. 5 MHz Johanson Tech. VCO 191 -2650 (Sirenza) VCO 2642. 5 MHz AFC EMLAB