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

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The MBMS was designed to eliminate the need for operators to introduce new hardware into their networks. It is a solution for transferring light video and audio clips, although real streaming is also possible. An important feature of MBMS is that it can be multiplexed with existing services on the same carrier. This will allow operators to offer voice, data and TV over a common service and network infrastructure. For heavy streaming in a wide area for a large and concentrated audience the DVB-H system, which is the main alternative to MBMS, is more suitable. Practical network implementations may be expected by the third quarter of 2007 and the first terminal to be available the third quarter the year after. According to estimations 30% of the terminals will support MBMS the year 2010 [22, 23]. 18
2.3 Antenna theory This section describes basic antenna theory, to easier understand later discussions. 2.3.1 Efficiency, directivity and gain Radiation efficiency ηrad is defined as the ratio between the radiated power Prad and the power accepted by the antenna Pin (see figure 2.8) P rad η rad = (2.1) Pin The directivity D and the gain G of an antenna are connected to each other by ηrad as G = ηrad D (2.2) Directivity describes the directional property of an antenna and the gain takes into account the losses in the antenna structure. For an ideal antenna the gain and the directivity are equal. Figure 2.8. Voltage reflection from a mismatched load. Γ is the refection coefficient, ZL and Z0 are the impedances of the load and transmission line, respectively. Pt, Pin and Prad are the (total) incident power to the load, the power accepted by the load and the power radiated by the load, respectively. 2.3.2 Reflection from a mismatched antenna The antenna impedance, ZL, must be equal to the characteristic impedance for the transmission line feeding the antenna, Z0, otherwise part of the voltage will be reflected from the antenna. How large this reflected voltage is can be measured in a network analyser as the parameter S11. The reflection coefficient can be calculated with following equation: Z Z − Z + Z L 0 Γ = (2.3) L 0 19
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: 2.2 Competing standards The DVB-H s
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 and 52: using an H-field antenna together w
Page 53 and 54: antenna. The dimension of the anten
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 71 and 72: Figure 5.12. 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 77 and 78:
Figure 5.22. Radiation pattern for
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
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Design of Antennas for Handheld DVB-H ... - Lunds tekniska högskola

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