Design of Antennas for Handheld DVB-H ... - Lunds tekniska högskola

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Return Loss /dB 0 -2 -4 -6 -8 -10 -12 -14 -16 Matching networks 450 480 510 540 570 600 630 660 690 720 Frequency /MHz 44 Matching network 1 Matching network 2 Matching network 3 Matching network 4 Figure 4.19. Example of four different matching circuits covering the DVB-H frequency band. The first switched monopole has no switches so soldering was needed to be able to switch between the matching circuits. This first prototype was built just to verify that this concept was possible for a DVB-H antenna, a picture of the antenna can be seen in figure 4.20 Figure 4.20. Switched monopole without RF switches. The ground plane used for all of the switched monopole prototypes is 110*60 mm and the antenna element is 70*10 mm. The dimensions of the antenna element are very important parameters for the antenna characteristic, the length affects the resonance frequency and the width of the element affects the bandwidth of the
antenna. The dimension of the antenna element was chosen so it fits in a normal handheld device. If it had been possible with a wider antenna element it had maybe been enough with two or three matching networks instead. The distance between the antenna element and the ground plane is an important parameter for the antenna characteristic, the longer the distance the better the performance, both deeper and wider return loss graph. All switched monopole prototypes have been built with a distance between ground plane and the antenna element of 3 mm. After designing the four different matching circuits, as shown in the schematic in figure 4.21 with component values according to table 4.1, the return loss was measured. The result of the return loss measurement is presented in figure 4.22. Figure 4.21. Schematic for four matching circuits for the switched monopole concept. Table 4.1. Value of components for the three different switched monopole prototypes. Circuit 1 Circuit 2 Circuit 3 Circuit 4 without RF switches Switched monopole 1 Switched monopole 2 C1 L1 C2 /pF /nH /pF /nH /pF /nH /pF /nH 12 19.5 10 15 8 11.2 7 7.5 45 L2 12 12 10 10 7 8.2 6 4.7 10 15 10 8.2 7 3.9 6 0 C3 L3 C4 L4
Page 1 and 2: Design of Antennas for Handheld DVB
Page 3 and 4: Acknowledgements This master thesis
Page 5 and 6: 4 DESIGN AND TESTING OF ANTENNA SOL
Page 7 and 8: Figure 5.2. Reference dipole antenn
Page 9 and 10: 1 Introduction The passed decade th
Page 11 and 12: 2 Background This chapter provides
Page 13 and 14: is simultaneously modulated into 10
Page 15 and 16: 2.1.3 Reed-Solomon Codes 2.1.4 DVB-
Page 17 and 18: 2.1.5 DVB-H DVB-H is the latest dev
Page 19 and 20: 2.1.5.2 Time slicing A large proble
Page 21 and 22: figure 2.5). All three elements tog
Page 23 and 24: symbols or four 2K OFDM symbols. Th
Page 25 and 26: 2.2 Competing standards The DVB-H s
Page 27 and 28: 2.3 Antenna theory This section des
Page 29 and 30: Figure 2.9. Impedance bandwidth def
Page 31 and 32: unloaded quality factor (Q0) and th
Page 33 and 34: losses should be avoided in handhel
Page 35 and 36: 3.3 Loop Figure 3.1. Yagi-Uda anten
Page 37 and 38: PIFA Figure 3.2. Four different con
Page 39 and 40: The size of the antenna is another
Page 41 and 42: 4.4 PIFA To verify the balun a resi
Page 43 and 44: 4.5 Folded-Patch With the PIFA-ante
Page 45 and 46: Figure 4.9a. Folded-patch 2, front
Page 47 and 48: Figure 4.11. Loop antenna schematic
Page 49 and 50: Figure 4.15. Wire loop antenna retu
Page 51: using an H-field antenna together w
Page 55 and 56: The result of the return loss measu
Page 57 and 58: Figure 4.24. Return loss graph for
Page 59 and 60: The result of the measurement of th
Page 61 and 62: Figure 4.31. Return loss graph for
Page 63 and 64: frequency band, the first from 470
Page 65 and 66: Figure 5.6. Radiation pattern for R
Page 67 and 68: 5.1.3 Measurement result In this ch
Page 69 and 70: Figure 5.10. Radiation pattern for
Page 73 and 74: Table 5.4. Switched monopole 1, gai
Page 75 and 76: Power gain / dB 2 0 -2 -4 -6 -8 -10
Page 79 and 80: was received in all five channels.
Page 81 and 82: 6.3 Control signal 6.4 Cost The swi
Page 83 and 84: not be possible, there will always
Page 85 and 86: There are many advantages with tuna
Page 87 and 88: 8 References [1] Schiller, Jochen -
Page 89: [29] Gardiol, Fred - Microstrip cir

Design of Antennas for Handheld DVB-H ... - Lunds tekniska högskola

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