Microstrip Filter Design Tool is a web-based application for distributed-element microstrip filter synthesis. It is feature rich, user-friendly and available
for free from any desktop or mobile device.

**Please note:**
- This tool is still in beta so use it with caution.
- Conductor and substrate losses are not yet modeled.
- The design is a first approximation and should be subsequently verified/optimized in a 3D electromagnetic simulation.
- If you face any issues please let us know through the contact page.

### Features

- One-click synthesis from a given specifications
- Precise layout dimensions on any dielectric substrate
- Interdigital topology
- Chebyshev or Butterworth filter types
- Arbitrary input and output impedances

### Contents

### 1 Lowpass Filters

### 1.1 Stubs (semi-lumped)

#### 1.1.1 Layout

**W0** - input and output feed-lines width.

**W1** - series lines width.

**W2** - stubs width.

**Sk** - the *k*th stub length, where the stubs are numbered from left to right starting with 1.

**Lk** - the *k*th line length, where the lines are numbered from left to right starting with 1.

#### 1.1.2 Special Parameters

**Line Low Impedance (Ω)** - the characteristic impedance of the low impedance lines.

**Line High Impedance (Ω)** - the characteristic impedance of the high impedance lines.

**Line Order** - control whether the leftmost section is a low impedance line or a high impedance line.

### 1.2 Stepped Impedance

#### 1.2.1 Layout

**W0** - input and output feed-lines width.

**W1** - high impedance lines width.

**W2** - low impedance lines width.

**Lk** - the *k*th line length, where the lines are numbered from left to right starting with 1.

#### 1.2.2 Special Parameters

**Line Low Impedance (Ω)** - the characteristic impedance of the low impedance lines.

**Line High Impedance (Ω)** - the characteristic impedance of the high impedance lines.

**Line Order** - control whether the leftmost section is a low impedance line or a high impedance line.

### 2 Bandpass Filters

### 2.1 Interdigital

#### 2.1.1 Layout

**W0** - input and output feed-lines width.

**W** - resonators width.

**L** - resonators length.

**e** - the extension in length of the leftmost and rightmost resonators.

**t** - the input and output feed-lines tapping point.

**Sk** - the spacing between the *k*th and *(k+1)*th resonators, where the resonators are numbered from left to right starting with 1.

#### 2.1.2 Special Parameters

**Resonator Impedance (Ω)** - the characteristic impedance of the resonators.

© 2017-2022 Marki Microwave, Inc. | Privacy Policy