Test Report for AT2800USB/AT2800PCI DVB-T Modulators

Specifications

Modulation specifications:

  Constellations:               QPSK, QAM16, QAM64

Transmission Modes:     IFFT:     2K, 8K non-hierarchical

Guars Intervals:              1/4, 1/8, 1/16, 1/32

FEC Code Rates:           1/2, 2/3, 3/4, 5/6, 7/8

Band Widths:                8MHz, 7HMz, 6MHz, 5MHz

Spectral Inversion:          non-inverted, inverted

  DVB inputs:

1:         DVB-ASI, BNC75 Ohm, 0-max. DVB-T bit rate

2:         DVB-SPI, LVDS, 25-pins SUB-D, 0-max. DVB-T bit rate

Note:    When modulating from an external DVB-ASI/SPI source the maximum input bit rate may not exceed that of DVB-T standard bit rate.

  DVB outputs:

1:         DVB-ASI, BNC75 Ohm, 0-max. DVB-T bit rate.

IF ouput:

Connector:                        BNC, 75Ohm

Frequency Ranges:        35-37MHz, adjustable in 1Hz steps

                                         69-71MHz, adjustable in 1Hz steps

Output Level:                 -1.75dBm

  RF ouput:

Connector:                        BNC, 75Ohm

Frequency Ranges:        50 to 1000MHz, adjustable in 1Hz steps

Output Level:                 + 0dBm to - 45dBm, adjustable in 0.5dB steps

Note:                                      When the IF & RF outputs are simultaneously used, the RF output should be
tuned to a multiple of 1MHz. The IF output frequency will be 70MHz than.

1         IF spectrum measurements

1.1      Phase noise and spur level for 66MHz carrier

Test conditions:

• Single carrier at 66MHz.
• IF Output impedance 75Ohm. Measurement input impedance: 50Ohm.

  Measured output levels:

• 66MHz:            -1.75    dBm
• 132MHz:          -45.2    dBm
• 198MHz:          -40.0    dBm
• 264MHz:          -56.4    dBm
• 330MHz:          -49.0    dBm
• 396MHz:          -71.5    dBm
• 462MHz:          -54.2    dBm
• 528MHz:          -80.0    dBm
• 594MHz:          -57.2    dBm

  Phase Noise:

• 100Hz:             -48       dBc                  note: 30Hz RBW on spectrum analyser
• 200Hz:             -58       dBc                  note: 30Hz RBW on spectrum analyser
• 300Hz:             -63       dBc                  note: 30Hz RBW on spectrum analyser
• 400Hz:             -65       dBc                  note: 30Hz RBW on spectrum analyser
• 500Hz:             -65       dBc                  note: 30Hz RBW on spectrum analyser
• 1kHz:               -68       dBc
• 10kHz:             -80       dBc
• 100kHz:           -95       dBc
• 1MHz:              -95       dBc

  1.2      Spur levels for 70MHz DVB-T modulated signal

Test conditions:

• modulated 8MHz DVB-T signal at 70MHz.
• IF Output impedance 75Ohm. Measurement input impedance: 50Ohm.

Signal Spur level:        -48dBc.           (2nd harmonic)

Signal Spur level:        -52dBc.           (3rd harmonic)

1.3      Spur levels for 36MHz DVB-T modulated signal

Test conditions:

• modulated 8MHz DVB-T signal at 36MHz.
• IF Output impedance 75Ohm. Measurement input impedance: 50Ohm.

Signal Spur level:        -50dBc.           (2nd harmonic)

Signal Spur level:        -45dBc.           (3rd harmonic)

Signal Spur level:        -30dBc.           (228MHz)

Signal Spur level:        -37dBc.           (300Mhz)

2         RF measurements

2.1      Phase noise and spur level for 100MHz carrier

      Test conditions:

• Single carrier at 100MHz.
• RF Output impedance 50Ohm. Measurement input impedance: 50Ohm.
• Ouputlevel: 0dBm.

    Measured output levels:

• 100MHz:          -0.2      dBm
• 200MHz:          -36.5    dBm                (2th harmonic)
• 232MHz:          -46.0    dBm                (RF carrier + 2th harmonic of IF)
• 300MHz:          -44.0    dBm                (3th harmonic)
• 400MHz:          -60.0    dBm                (4th harmonic)
• 500MHz:          -68.0    dBm                (5th harmonic)

Phase Noise:

• 100Hz:             -42       dBc                  note: 30Hz RBW on spectrum analyser
• 200Hz:             -60       dBc                  note: 30Hz RBW on spectrum analyser
• 300Hz:             -61       dBc                  note: 30Hz RBW on spectrum analyser
• 400Hz:             -63       dBc                  note: 30Hz RBW on spectrum analyser
• 500Hz:             -64       dBc                  note: 30Hz RBW on spectrum analyser
• 1kHz:               -64       dBc
• 10kHz:             -92       dBc
• 100kHz:           -98       dBc
• 1MHz:              -100     dBc

2.2      Spur levels for 100MHz DVB-T modulated signal

Test conditions:

• modulated 8MHz DVB-T signal at 100MHz.
• RF Output impedance 50Ohm. Measurement input impedance: 50Ohm.

Spur level:                   -65dBc.

Signal Spur level:        -45dBc.

  LO suppression level: -30dBc. (static at 1220MHz, modulated signal)

RF suppression level: -28bBc. (sweeping, at 1320MHz)