TUA6039 Infineon Technologies Corporation, TUA6039 Datasheet - Page 6

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

1.2. UHF RF Block
without coupling diodes and without compensating coils for extending the frequency ratio in the tuned
filters. To get a good tracking without a coupling diode between the input filter and the MOSFET the
point of coupling is set between the tuning diode and the series capacitor, and not at the high end of the
resonant circuit.
transformation from unbalance to balance. Also due to the matched image filters on both pre-stage and
band-pass filter stage, better than 50dB image rejection can be achieved over the whole UHF band. By
means of simple gate-1 switching through PNP ports, pre-amplifiers are selected.
1.3. VHF High RF Block
one additional coupling diode, BB565 is placed on the pre-stage of VHF High.
like UHF band pass filter. The coupling between filters is realized via a printed inductor. The mixer input
circuit is optimized to protect the mixer from overloading. Image rejection filters work as those of UHF
block.
1.4. VHF Low RF Block
BB689 is a tuning diode, which was developed to cover the wide frequency range of Hyperband tuner
and at the same time shows a low series resistance. 2 X BB565 are used for coupling to achieve
improved RF characteristics.
Low mixer, which has no negative effects due to the relatively low frequencies involved.
After the RF Block circuit design it is preferable to do block simulations to confirm its frequency
dependent characteristics. Fig.2 is one of such simulation results.
The RF band-pass filter is unbalanced on the primary side, and balanced on the secondary side just
The RF band pass filter is unbalanced, and is also coupled asymmetrically to the high impedance VHF
For VHF High band, high quality ratio-extended varactor diode, BB659C is used. To compensate gain,
The band-pass stage is an inductive low end coupling filter, which concurrently provides the
For the wide VHF Low frequency range a tuning diode with an extended capacitance ratio is required.
With the wide range ultra linear varactor diode BB565 it has become possible to design an UHF band
Fig. 2 One of the Simulation Results of DVB-T Half NIM RF Blocks
Application Notes Revision 3.0
Application Engineering
5
Communication Solutions
IFAP COM Tuner Systems
May 2007