#include <uhd/types/tune_request.hpp>
A tune request instructs the implementation how to tune the RF chain. The policies can be used to select automatic tuning or fine control over the daughterboard IF and DSP tuning. Not all combinations of policies are applicable. Convenience constructors are supplied for most use cases.
See also Tuning Notes
◆ policy_t
Policy options for tunable elements in the RF chain.
Enumerator |
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POLICY_NONE | Do not set this argument, use current setting.
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POLICY_AUTO | Automatically determine the argument's value.
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POLICY_MANUAL | Use the argument's value for the setting.
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◆ tune_request_t() [1/2]
uhd::tune_request_t::tune_request_t |
( |
double |
target_freq = 0 | ) |
|
Make a new tune request for a particular center frequency. Use an automatic policy for the RF and DSP frequency to tune the chain as close as possible to the target frequency.
- Parameters
-
target_freq | the target frequency in Hz |
◆ tune_request_t() [2/2]
uhd::tune_request_t::tune_request_t |
( |
double |
target_freq, |
|
|
double |
lo_off |
|
) |
| |
Make a new tune request for a particular center frequency. Use a manual policy for the RF frequency, and an automatic policy for the DSP frequency, to tune the chain as close as possible to the target frequency.
- Parameters
-
target_freq | the target frequency in Hz |
lo_off | the LO offset frequency in Hz |
◆ args
The args parameter is used to pass arbitrary key/value pairs. Possible keys used by args (depends on implementation):
- mode_n: Allows the user to tell the daughterboard tune code to choose between an integer N divider or fractional N divider. Default is fractional N on boards that support fractional N tuning. Fractional N provides greater tuning accuracy at the expense of spurs. Possible options for this key: "integer" or "fractional".
◆ dsp_freq
double uhd::tune_request_t::dsp_freq |
The DSP frequency in Hz. Set when the policy is set to manual.
Note that the meaning of the DSP frequency's sign differs between TX and RX operations. The target frequency is the result of target_freq = rf_freq + sign * dsp_freq
. For TX, sign
is negative, and for RX, sign
is positive. Example: If both RF and DSP tuning policies are set to manual, and rf_freq
is set to 1 GHz, and dsp_freq
is set to 10 MHz, the actual target frequency is 990 MHz for a TX tune request, and 1010 MHz for an RX tune request.
◆ dsp_freq_policy
policy_t uhd::tune_request_t::dsp_freq_policy |
The policy for the DSP frequency. Automatic behavior: the difference between the target and IF.
◆ rf_freq
double uhd::tune_request_t::rf_freq |
The RF frequency in Hz. Set when the policy is set to manual.
◆ rf_freq_policy
policy_t uhd::tune_request_t::rf_freq_policy |
The policy for the RF frequency. Automatic behavior: the target frequency + default LO offset.
◆ target_freq
double uhd::tune_request_t::target_freq |
The target frequency of the overall chain in Hz. Set this even if all policies are set to manual.
The documentation for this struct was generated from the following file: