SC5305A Operating & Programming Manual
Rev 2.1.0
45
Function:
sc5305a_CalcIfResponseCorrection
Definition:
int sc5305a_CalcIfResponseCorrection(float *offsetFrequencies, unsigned int nPoints,
bool ifFil1PathEnable, calibrationData_t *calData,
ifResponseCorrect_t *correctedIfResponse)
Input
:
float *offsetFrequencies
(floating point number 1-D array)
unsigned int nPoints
(number of points in the 1-D array)
bool ifFil1PathEnable
(IF filter 1 path enable)
calibrationData_t *calibrationData
(calibration data for the device)
Output
:
float *correctedIfResponse
Description
:
sc5305a_CalculateIfResponseCorrection
determines the IF correct response for the set
of IF offset frequencies. These offset frequencies may be the frequency components of
an FFT of the acquired data being offset from its center frequency. To obtain the offset
frequencies, one can simply subtract the frequencies from the IF center frequency. For
example, if a digitizer sampling at 100 MHz is used to digitize the 70 MHz IF signal with
bandwidth of 3 MHz, the center of the digitized signal is 30 MHz +/- 1.5 MHz. After
performing digital spectral inversion and performing an FFT, take the subset of
frequency components from 28.5MHz to 31.5 MHz and subtract 30 MHz to obtain the
offset frequencies of -1.5 MHz to 1.5 MHz. Use this set of offset frequencies to compute
the gain and phase corrections to be applied to the original signal spectrum at 28.5 MHz
to 31.5 MHz. This algorithm may not be sufficient for computation of broadband signals
due to the lack of computation speed and correction accuracy. The calibration stored
does not account for in-band phase and amplitude variations due to temperature and
these variations may cause sufficient errors, especially in broadband digital signals. The
user should apply in situ equalization to correct for the in-band amplitude and phase
errors.
Function:
sc5305a_ConvertRawTempData
Definition:
int sc5305a_ConvertRawTempData(unsigned int rawTempData, float *temperature)
Input
:
unsigned int rawTempData
(16-bit rawTempData stored in a 32-bit unsigned int)
Output
:
float *temperature
(temperature value of the device in degrees Celsius)
Description
:
sc5305a_ConvertRawTempData
converts the rawTempData variable into a floating
point number.
