2

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l

l FFT

l

l EMI

3

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lll

4

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l

l EMI

Amp

Digital I/ODigital I/O

Digital I/O DAC

RF Tx Out

System IndicatorSystem

Indicator

I2C/SPI CLK

I2C/SPI DATA

Mic

ro-C

ontr

olle

r Uni

tPLL PLL

FiltersFilters

PLL Ref Osc Processing Control

5

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lllll FFT

llllll

6

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FFT 0Hz DC-1/2 .FFT

FFT

FFT :

(FFT )

FFT )

7

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R&S RTO FFT

FFTFFT

RTO :

FFT )

8

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RTO FFT

I RTC FPGAI

FFT

ADCAmp

MATH

RTC

FPGAFFT

CPU

9

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l FFTlll

FFT 1 FFT 2 FFT 3 FFT 4

single acquisition

FFT 1FFT 2

FFT 3FFT 450% overlapping

RTO FFT

10

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FFT vs FFTf(x)

t

f(x)

f

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

t

f(x)

f

f(x)

f

f(x)

f

f(x)

f

f(x)

f

windowing

FFT FFT

…

FFT

… …

+

+

+

+

RTO FFT

FFT

FFTFFT

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II ADCI ADC ADC (as artifacts in FFT spectrum)II

I RTOI ENOB> 7 bitsI

I 1/4I >60dB

RTO FFT

12

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: 500 MHz -25dBm: 5mV/div & 2us/div

FFT : Center Freq = 1GHz, Span of 1GHz, Resolution BW 100kHz

10Gs/s

1 2

3 410GS/s ADC 10GS/s ADC

1

13

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:

•

Example:

Sample rate = 10Gs/s Frequency Span = 10 MHz

In bits this means:

100010

/10MHz

sGspanFrequencyS

SampleRateGainDecimation

9.9)1000(2LogGainBits

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?

1) :

Example: 256 averages lowers the noise floor about 24 dB

2) .

Memory depth = Magnitude of asynchronous noise = Dynamic range

Example: x2 Memory depth = -3 dB of noise

dBLogdBNLogdBN avgfl 24)256(*3)(*3 22

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Averaging OFF FD Averaging ON, Count = 256

100 MHz CW Carrier, -10 dBm

16

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Averaging OFF TD Averaging ON, Count = 256

100 MHz CW Carrier, -10 dBm

24 dB

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Record Length: 1 kSa Record Length: 10 kSa Record Length: 100 kSa

10 MHz CW Carrier, -10 dBm

18

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RTO FFT

l

l

l

Center = 2,4 GHz Span = 50 MHz

Fast frequency hopper100.000 hop/sec

Gated FFT view to analyze the durationof each frequency setting

11 hop frequencies, 1 MHz spacing, 10 us interval

FFT view ofentire record

19

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ll

RTO

20

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EMI

RTO

21

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Center = 2,4 GHz Span = 50 MHz

(THD)

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Center = 2,4 GHz Span = 50 MHz

Fast frequency hopper100.000 hop/sec

Gated FFT view to analyze the durationof each frequency setting

11 hop frequencies, 1 MHz spacing, 10 us interval

Fast hopping frequency synthesizer

FFT view ofentire record

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– AM

Center = 245 kHz Span = 10 kHz Center = 5 kHz Span = 10 kHz

245 kHz AM modulated carrier

1 kHz modulation signal

AM modulated carrier

Modulation signal + harmonics

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– FM

Center = 96.5 MHz Span = 1 MHz

96.5 MHz FM modulated carrier

1 kHz modulation rate250 kHz deviation

FM deviation

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– GSM burst

Center = 850 MHz Span = 2 MHz

Single GSM timeslot

FFT envelope mode

FFT normal mode

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– WLAN 802.11g

Center = 2.4 GHz Span = 50 MHz

Bluetooth Signal hidden behind 802.11b WLAN Signal

27

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Center = 2,4 GHz Span = 50 MHz

500 MHz Carrier

Pulse period 10 usPulse width 1 us Span = 20 MHz

Span = 4 MHz

Pulse Width

Pulse Period

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l

-

VCO

29

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PLL #1

VCO Input = 1.9V

830MHz 830MHz 830MHz

VCO RF

FFT

SPI

MOSISPI

VCO

30

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PLL #1

VCO Input

830MHz 830MHz 840MHz

VCO RF

Gated FFTFrequency Domain

SPI Clock

MOSI

Protocol Decode

SPI Serial bus ControlSignal to VCO

1.9V2.7V

480us PLL Settling Time

480us PLL Settling Time

31

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l VCO

- VCO

32

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l VCO

1

4 VCO

- VCO

33

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l

Use SmartGrid for easier viewing

- VCO

34

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l VCO

Use SmartGrid for easier viewing

FFT

FFT

- VCO

35

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l

Use SmartGrid for easier viewing

2.397GHz 2.4GHz

- VCO

36

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l

- VCO

37

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l VCO

!!!

- VCO

38

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l FFT

2 gated FFT Full FFT

- VCO

39

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l

FFT

- VCO

40

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EMI

EMI l EMI

l EMI

l EMI

ll

ll RTO

l HZ-15

41

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EMI

l

-DUT EMI EMI

l-- EMI

Electric field Probe Magnetic field Probe

42

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PCB

/

EMI

43

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40MHz Clk Chip

40MHz

, 40MHz

44

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EMI -

MOFET -

Less Occur

Frequently Occur

MOFETLC

45

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EMI – FFT

400ns Pulse

Gated FFT

FFT

Gated FFT

Time Domain

Time Domain

Frequency Domain

Frequency Domain

130MHz

100MHz180MHz

200MHz

46

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EMC

47

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9KHz-1MHz• Conducted Emission using LISN

• 9 kHz – 1 MHz

• FSV trace 1 = Max hold / Pos Peak RTO FFT1 = Normal mode

• FSV trace 2 = Clear Write / Auto Peak RTO FFT2 = Envelope mode

EN55015Q

48

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EMI

l FFT EMI

Oscilloscope FFT

ESPI EMI Tester

NOTE:

EMIEMI

ESPI EMI Tester

ESPI EMI Tester

49

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Center = 2,4 GHz Span = 50 MHz

FFT FFT

FFT

50

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l

l FFT

l RTO

l FFT

RTO

EMI