---
title: "Short note: E-plane tee against H-plane tee"
subject: "RF and Microwave Engineering"
chapter: 4
key: "semester_7/rf_and_microwave_engineering:eplane-vs-hplane-tee-note"
source: https://www.bctengineer.com/q/semester_7/rf_and_microwave_engineering/eplane-vs-hplane-tee-note
site: BCT Engineering
---

# Short note: E-plane tee against H-plane tee

RF and Microwave Engineering · Chapter 4: RF and Microwave Components and Devices

- Asked in: 2069 Bhadra (old course), 5 marks
- Video: [Experiment of E-Plane Tee, H-Plane Tee, and Magic Tee](https://www.youtube.com/watch?v=aC_KFRfxg2w) — Amiya Sir's Video Lectures
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/rf_and_microwave_engineering/eplane-vs-hplane-tee-note
- Whole chapter: https://www.bctengineer.com/md/semester_7/rf_and_microwave_engineering/chapter-4

## Question

Write a short note on E-plane tee against H-plane tee.

## Short answer

In an E-plane tee the side arm joins the broad wall, acting as a series junction; a signal at port 3 splits into ports 1 and 2 with 180° phase difference, and port 3 delivers the difference of inputs. An H-plane tee has the side arm on the narrow wall, works as a shunt junction, splits in phase, and port 3 gives the sum.

## Answer

A waveguide **tee** is a three-port junction made by joining a side arm to a main rectangular waveguide. In an **E-plane tee** the side arm lies in the plane of the E-field. In an **H-plane tee** it lies in the plane of the H-field.

```text
 E-plane tee (series)     H-plane tee (shunt)
        port 3                   port 3
         ||                       ||
 ====[  top  ]====       ====[ side  ]====
 port 1      port 2      port 1      port 2
 arm on broad wall       arm on narrow wall
```

**E-plane tee (series tee)**
- The side arm is joined to the **broad wall**, parallel to the E-field of the main guide.
- A signal fed into port 3 splits equally into ports 1 and 2, but the two outputs are **180° out of phase**.
- In-phase equal signals at ports 1 and 2 cancel at port 3. Out-of-phase signals add at port 3, so port 3 gives the difference (Δ) of the inputs.
- It acts like a **series** connection.

**H-plane tee (shunt tee)**
- The side arm is joined to the **narrow wall**, so its axis is parallel to the H-field plane.
- A signal fed into port 3 splits equally into ports 1 and 2 **in phase**.
- In-phase signals at ports 1 and 2 add at port 3, so port 3 gives the sum (Σ).
- It acts like a **shunt (parallel)** connection.

| Point | E-plane tee | H-plane tee |
|---|---|---|
| Side arm on | Broad wall | Narrow wall |
| Equivalent circuit | Series junction | Shunt junction |
| Port 3 input → ports 1, 2 | Equal, 180° apart | Equal, in phase |
| Port 3 output | Difference (Δ) | Sum (Σ) |
| S-matrix sign | S₁₃ = −S₂₃ | S₁₃ = S₂₃ |

Combining the two gives the **magic tee** (hybrid tee), used in mixers, duplexers and impedance bridges.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Signal fed into port 3 of an E-plane tee gives outputs at ports 1 and 2 that are:
   A. Equal and in phase
   B. Equal and 180° out of phase
   C. Unequal
   D. Zero
   Answer: B. The E-plane tee acts as a series junction with S13 = −S23. (Key point: E-plane tee phase)

2. Where is the side arm of an H-plane tee attached?
   A. Broad wall
   B. Narrow wall, giving a shunt junction
   C. Both walls
   D. The end of the guide
   Answer: B. The H-plane tee is a shunt tee with the arm on the narrow wall; S13 = S23. (Key point: H-plane tee arm position)

3. Equal in-phase signals at ports 1 and 2 add at port 3 in:
   A. The E-plane tee
   B. Neither
   C. The H-plane tee (Σ); the E-plane tee gives a difference (Δ)
   D. Both give zero
   Answer: C. H-plane port 3 gives the sum; in the E-plane tee in-phase inputs cancel. (Key point: Sum and difference ports)

4. Combining the E-plane and H-plane tees gives:
   A. A directional coupler
   B. A magic tee (hybrid tee)
   C. An isolator
   D. A circulator
   Answer: B. The magic tee is the four-port hybrid of the two. (Key point: Combination)

## Related in RF and Microwave Engineering

- [S-matrices of E-plane tee, H-plane tee and duplexer](https://www.bctengineer.com/question.md?key=semester_7%2Frf_and_microwave_engineering%3Aeplane-hplane-tee-duplexer-smatrix) — RF and Microwave Engineering, chapter 4
- [Short note: E-plane tee](https://www.bctengineer.com/question.md?key=semester_7%2Frf_and_microwave_engineering%3Aeplane-tee-note) — RF and Microwave Engineering, chapter 4

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