TUA6039 Infineon Technologies Corporation, TUA6039 Datasheet - Page 7

• Manufacturer Part Number: TUA6039
• Description: Stationary - Mopll & Silicon Tuner
• Manufacturer: Infineon Technologies Corporation

1
2
1.5. Oscillator Resonator, PLL Loop Filter and Phase Noise
layout is also optimized to prevent any kind of unwanted parasitic oscillation. Capacitors of the resonators
could be temperature-compensated if necessary. N750 type is recommended for this purpose.
RF signals to IF frequency with minimum phase noise. The DVB-T standards provides for two modes of
operation, a 2K mode with 1705 sub-carriers, and an 8K mode with 6817 sub-carriers for
OFDM(Orthogonal Frequency Division Multiplexing) transmission
multiple sub-carriers, each of which is a smaller percentage of the total frequency bandwidth than in a
single carrier system. As a result, phase noise is a smaller percentage of the bandwidth in a single-carrier
system. For this reason, phase noise degrades the performance of an OFDM system more than in a
single carrier system.
mixing in Fig.4, and the other is receiver sensitivity or SNR
digital system combined with other noise sources like pre-stage noise figures, image noise, etc.
considered. Even though there is an improved phase noise model
prediction, Leeson's equation is still a basis of all those new approaches.
. ETSI EN 300 744 V1.2.1
. Muschallik, C., Influence of RF oscillators on an OFDM signal, IEEE Transactions on Consumer Electronics, vol.41,No.3, pp.602-
One of the most important considerations to design a good DVB-T tuner is how to down-convert input
603
The Oscillator tank circuits were carefully optimized for oscillator range, stability and phase noise. The
Phase noise influences two important system performances: One is receiver selectivity by reciprocal
To design optimum resonators for the IC, the well-known Leeson's equation
Input Signals
Application Notes Revision 3.0
Fig. 3 Typical Spectrum of the simple OFDM signal
Fig. 4 Reciprocal Mixing Model
Application Engineering
Local Oscillator
Tuner
6
2
, which decides BER (Bit-Error-Rate) of the
1
4
. An OFDM signal as in Fig.3 contains
for better phase noise analysis and
Output Signals
Communication Solutions
IFAP COM Tuner Systems
3
should always be
May 2007