*Question E9H09:
What type of radiation pattern is created by a single-turn, terminated loop such as a pennant antenna?*  

*Correct Answer is  A: Cardioid*  

### AI Response: (may contain errors)  

The correct answer to the question about the radiation pattern created by a single-turn, terminated loop such as a pennant antenna is **Cardioid**. 

### Explanation of the Correct Answer:
- **Cardioid Pattern**: A single-turn, terminated loop antenna produces a cardioid radiation pattern. This means that the antenna radiates more power in one direction while having a null in the opposite direction. The shape resembles a heart (or cardioid), which is characteristic of antennas that are designed to focus energy in a specific direction.

### Why the Other Choices are Incorrect:
- **A: Bidirectional**: 
  - A bidirectional pattern typically has two lobes of radiation, one in each direction, with nulls in between. This is not the case for a single-turn loop, which has a more focused pattern.
  
- **C: Omnidirectional**: 
  - An omnidirectional pattern radiates equally in all directions in a horizontal plane. A single-turn loop does not radiate uniformly; it has a preferred direction, making this choice incorrect.
  
- **D: Hyperbolic**: 
  - A hyperbolic pattern is not a standard term used in antenna theory. Antenna patterns are usually described as omnidirectional, bidirectional, or unidirectional (like cardioid). Therefore, this option does not apply.

### Summary:
- The single-turn, terminated loop antenna creates a **cardioid** radiation pattern, focusing energy in one direction and having a null in the opposite direction. Understanding these patterns is crucial for effective antenna design and operation in amateur radio.