*Question E7F10:
What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a direct-sampling software defined radio (SDR)?*  

*Correct Answer is  A: Sample rate*  

### AI Response: (may contain errors)  

In a direct-sampling software defined radio (SDR), the maximum receive bandwidth is determined by the **sample rate**. Here's why:

### Explanation:

1. **Correct Answer: Sample rate (A)**
   - The sample rate, often denoted as $f_s$, is the number of samples per second taken from a continuous signal to make it discrete. According to the Nyquist-Shannon sampling theorem, the maximum bandwidth ($B_{\text{max}}$) that can be accurately captured by an SDR is half of the sample rate:
     $$B_{\text{max}} = \frac{f_s}{2}$$
   - This means that if you have a sample rate of 10 MHz, the maximum bandwidth you can receive is 5 MHz.

2. **Incorrect Choices:**
   - **Sample width in bits (B):** This refers to the resolution of each sample, which affects the dynamic range and the precision of the signal representation, but not the bandwidth.
   - **Integral non-linearity (C):** This is a measure of the deviation of the ADC's transfer function from a straight line. It affects the accuracy of the conversion but not the bandwidth.
   - **Differential non-linearity (D):** This measures the variation in step size between adjacent digital levels in an ADC. It impacts the linearity and precision of the conversion, not the bandwidth.

### Summary:
The sample rate is crucial for determining the maximum bandwidth because it dictates how frequently the signal is sampled, directly affecting the range of frequencies that can be accurately represented. Other factors like sample width and non-linearity affect the quality and accuracy of the signal representation but do not limit the bandwidth.