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SIGNALCORE SC5317A Скачать руководство пользователя страница 12

©2018

Rev 1.1

11

Functional Description

Figure 4. Block diagram of the downconverter assembly

The Input Path Switch

Immediately following the capacitor is a RF switch to selectively direct the RF signal down two paths:

1.

The default is the conversion path where the RF signal is converted to an IF.

2.

The alternative path is directly to the RF output port, bypassing all means of frequency
conversion. The upper frequency limit of this path is about 7 GHz, although path loss calibration is
only up to 6 GHz.

When the conversion path is bypassed, the conversion path and the internal LO are disabled by powering
down.

The RF Path

The first device in the RF conversion path is a step attenuator with 1 dB step resolution. This attenuator
(RF_ATTEN) is used to control the signal level at the mixer or at the RF preamplifier. If the RF level at the
input of these devices is relatively large with respect to their input compression points, the signal would
experience greater nonlinear effects, distorting its waveform, and producing large spurious 3

rd

intermodulation distortion effects.

Following RF_ATTEN is a switchable RF amplifier that can be switched into the signal path to improve the
device sensitivity, effectively lowering the device noise figure. In other words, the effective input noise
level of the device is lowered when this amplifier is enabled. When signals with levels lower than -30 dBm
are expected, turning on this amplifier is recommended to improve the signal-to-noise dynamic range
(DR

SNR

). The typical maximum gain of the downconverter without the amplifier enabled is +20 dB, and

when the amplifier is enabled, its addi20 dB will boost the typical maximum gain to +45 dB.

There are no band selective filters in the RF path so in open environments the device is unable to
differentiate a RF signal from its image. A band select filter at the RF input port is recommended to
properly filter out the signal of interest before down conversion.

R

I

L

2

RF_PREAMP

LNA

6-26.5 GHz

LPF

3.5 GHz

LPF

10 M - 3.5 GHz

RF_ATTEN

30 GHz DSA

0 to 31 dB

1 dB step

IF_ATTEN

6 GHz DSA

0 to 31.75 dB

.25 dB step

Front LO /
Reference

DC coupled

<13.5 GHz

>13.5 GHz

10 MHz
Reference In

Internal LO
Synthesizer

–

GHz

1 Hz step

LO Out

RF Bypass

Output

Rear LO

DC coupled

IF Out

~DC to 3.5 GHz

RF In

6 to 26.5 GHz

50



50



IF Amp

IF Amp

IF Amp

RF
Linear
Amp

LO
Buffer
Amp

LPF

50 MHz

HPF

6 GHz

~D

C

–

G

H

z

Byp

as

s

User

controlled

component

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Содержание SC5317A

Страница 1: ...2018 SignalCore Inc All Rights Reserved Hardware Manual SC5317A SC5318A 6 GHz to 26 5 GHz RF Downconverter www signalcore com SC5317A Coming Soon...

Страница 2: ...7 Signal Connections 7 Device LED Indicators 7 Communication and Supply Connection 8 Mini USB Connection 9 Reset Button Pin Hole 9 3 Functional Description 9 Overview 9 The Signal Chain 10 The RF Inpu...

Страница 3: ...NTH_SELF_CAL 21 Query Registers 21 Register 0x30 GET_DEVICE_PARAM 22 Register 0x31 GET_TEMPERATURE 22 Register 0x32 GET_DEVICE_STATUS 23 Register 0x33 GET_DEVICE_INFO 24 Register 0x34 CAL_EEPROM_READ...

Страница 4: ...rial Bridge 5 Writing to the Device 5 Reading from the Device 6 6 Calibration 6 Calibration EEPROM Map 6 Absolute Conversion Gain 7 Absolute Gain of the RF Conversion Path 8 Gain Through the Bypass RF...

Страница 5: ...THE PART OF SIGNALCORE INCORPORATED SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER SIGNALCORE INCORPORATED WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF P...

Страница 6: ...PBDE A indicates that the hazardous substance contained in all of the homogeneous materials for this product is below the limit requirement in SJ T11363 2006 An X indicates that the particular hazardo...

Страница 7: ...ORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION 2 Physical Description Unpacking All SignalCore products...

Страница 8: ...eaning is necessary use lint free swabs and isopropyl alcohol to gently clean inside the connector barrel and the external threads Do not mate connectors until the alcohol has completely evaporated Ex...

Страница 9: ...to the SC5318A is provided through a a rectangular connector from Samtec whose part number is TFM 115 01 L D RA It also serves as the digital connector interface for RS232 SPI trigger and other digita...

Страница 10: ...hole is the reset button only available on the SC5318A Using a pin to lightly depress this momentary action push button switch will cause a hard reset to the device putting it back to its default sett...

Страница 11: ...ter accuracy and stability the synthesizer can lock to an external reference of higher precision The Signal Chain The conversion module contains the mixers filters amplifiers and attenuators used to c...

Страница 12: ...itchable RF amplifier that can be switched into the signal path to improve the device sensitivity effectively lowering the device noise figure In other words the effective input noise level of the dev...

Страница 13: ...isolation lowering the LO leakage at the RF input port to 90 dBm The frequency relationship between the three ports of the mixer is given as From the above equation the IF output spectrum is inverted...

Страница 14: ...aintaining low phase noise The reference signal for the generation of the LO signal comes from an internal temperature controlled crystal oscillator TCXO Figure 5 Block diagram of the local oscillator...

Страница 15: ...t of hardware registers of the downconverter may be divided into a configuration set and a query set the configuration registers are write only registers to set up the states of the device while the q...

Страница 16: ...6 31 24 Frequency Word Hz 31 24 39 32 Frequency Word Hz 39 32 47 40 Frequency Word Hz 47 40 55 48 Frequency Word Hz 55 48 LO_FREQUENCY 0x12 7 0 Frequency Word Hz 7 0 15 8 Frequency Word Hz 15 8 23 16...

Страница 17: ...oscillator synthesizers It also enables or disables faster tuning of the YIG based oscillator of LO1 Bytes written 2 Bytes read 1 Bits Type Name Width Description 1 0 WO Loop Gain 2 0 low loop gain i...

Страница 18: ...rd in milli Hz mHz mHz used for future compatibility 7 0 R Read back byte 8 Read 1 byte back is required for PXIe and RS232 Register 0x12 LO_FREQUENCY This register sets the final IF value Bytes writt...

Страница 19: ...value 8 In 0 25 dB LSB for IF 1 dB LSB for RF 10 8 W The target attenuator 3 The attenuator number 0 RF Atten 1 RF Atten 23 11 W Unused 13 Set to zeros 7 0 R Read back byte 8 Read 1 byte back is requ...

Страница 20: ...written 2 Bytes read 1 Bits Type Name Width Description 7 0 W Unused 8 Set to zeros 7 0 R Read back byte 8 Read 1 byte back is required for PXIe and RS232 Register 0x19 DEVICE_STANDBY This register s...

Страница 21: ...zeros 7 0 R Read back byte 8 Read 1 byte back is required for PXIe and RS232 Register 0x1B REFERENCE_DAC This register makes adjustments to the 10 MHz TCXO accuracy via DAC to its tuning port Bytes w...

Страница 22: ...isters may require instruction data to specify the type of data to return while others do not need any For example the register GET_DEVICE_PARAM 0x30 returns the RF Frequency IF1 Frequency IF3 Frequen...

Страница 23: ...er to query from the device Bytes written 2 Bytes read 8 Bits Type Name Width Description 3 0 W Parameter 1 0 Returns current RF frequency 1 current IF frequency 2 current LO frequency 3 current Other...

Страница 24: ...The coarse tuning PLL of LO 2 R Pll status LO1 fine 1 The fine tuning PLL of LO 3 R Pll status VCXO 1 100 MHz VCXO 4 R Pll status TCXO 1 TCXO only valid when lock to external reference is enabled 6 5...

Страница 25: ...device 22 R autoAmpEnable 1 Only reflects the software setting for gain calculation does not affect device 63 23 R Invalid data 29 Ignore Register 0x33 GET_DEVICE_INFO Write to this register to query...

Страница 26: ...8 Zeros 63 0 R Data 64 8 bytes of data LSB is the byte at the start address Register 0x36 SERIAL_OUT_BUFFER Writing to this register only provides the 64 clock edges Reg 7 data bytes to transfer seri...

Страница 27: ...ertz Attenuator values Each attenuator value is returned as one byte and the lsb is in 0 25 dB Divide each byte by 4 to obtain the result in dB Signal Chain Configuration The signal chain configuratio...

Страница 28: ...vision Information The first 4 bytes represent the hardware revision and last 4 bytes represent the firmware revision of the device These 4 bytes encompass a 32 bit floating point number so the data n...

Страница 29: ...2018 SignalCore Inc All Rights Reserved Section 2 Communication Interfaces and Calibration...

Страница 30: ...ollowing 1 Frequency is sent in 1000th of Hertz so the data that represents the frequency is 12 000 000 000 000 milli Hertz 2 This number can be represented by a 64 bit unsigned long and in Hexadecima...

Страница 31: ...rthermore pin must be asserted low for the entire duration of a register transfer Once a full transfer has been received the device will proceed to process the command and de assert low the SRDY pin T...

Страница 32: ...es depends on the register being targeted The first byte sent is the register address and subsequent bytes contain the data associated with the register As data from the host is being transferred to t...

Страница 33: ...is pulled low or grounded the rate is set to 115200 upon reset or power up Data bits The number of bits in the data is fixed at 8 Parity Parity is 0 zero Stop bits 1 stop bit Flow control 0 zero or no...

Страница 34: ...en 0x00 and 0xFF from BAR0 which is memory mapped A kernel level driver for the operating system is needed to access this memory address A simple driver using IO controls should be sufficient to read...

Страница 35: ...at later received data are not corrupted Section 5 5 3 1 describes how a byte read cycle is performed Reading from the Device Device data is passed back to the host via the bridge chip byte by byte so...

Страница 36: ...xF08 83 332 Float_32 RF invert abs gain each rf cal freq 0x1240 83 332 Float_32 Rf rel amplifier gain each rf cal freq 0x1578 2490 9960 Float_32 RF atten 1 30 dB 1 dB step for each freq a1_f0 a1_f1 a1...

Страница 37: ...m the absolute reference values made over various RF frequencies These relative values are either subtracted attenuation or added gain to the absolute gain value to determine the gain of the relative...

Страница 38: ...rence is computed using 1 1 0 1 2 0 2 is the gain correction 1 1 and 1 2 are the first and second order temperature gain coefficients respectively for RF band 1 and and 0 are the current temperature a...

Страница 39: ...A SC5318A Hardware Manual SignalCore Inc 10 SC5317A SC5318A Hardware Manual Revision Table Revision Revision Date Description 0 1 6 19 18 Document Created 1 0 9 12 18 Initial Release 1 1 9 24 18 Edite...

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