Antenna Handbook

2-Element Yagi Array Antenna Calculator: A Complete Guide (2025 Edition)



Yagi-Uda antennas—commonly known as Yagi antennas—have long been a preferred choice for applications ranging from ham radio and amateur television to Wi-Fi and satellite communication. Among the simplest yet most effective designs is the 2-element Yagi array, consisting of a driven element and a reflector or director. This configuration is popular due to its balance between simplicity, gain, and directionality.

In this article, we will explore everything you need to know about the 2-element Yagi array antenna calculator: how it works, the physics behind it, the math involved, and how to use an online calculator to design your own high-performance antenna.

Table of Contents

  1. What is a Yagi-Uda Antenna?

  2. Components of a 2-Element Yagi Array

  3. Why Use a 2-Element Yagi?

  4. Key Parameters in Yagi Design

  5. Mathematical Formulas for a 2-Element Yagi

  6. How the 2-Element Yagi Calculator Works

  7. Step-by-Step Example Calculation

  8. Applications of 2-Element Yagi Antennas

  9. Benefits and Limitations

  10. Top Online Yagi Antenna Calculators

  11. Final Tips and Best Practices

1. What is a Yagi-Uda Antenna?

A Yagi-Uda antenna, or simply a Yagi antenna, is a directional antenna system made up of:

  • A driven element (typically a half-wave dipole)

  • One or more passive elements, which include:

    • A reflector (placed behind the driven element)

    • One or more directors (placed in front of the driven element)

Yagi antennas are widely used for their ability to focus signal energy in one direction, offering high gain and directivity.

2. Components of a 2-Element Yagi Array

The 2-element Yagi is the most basic configuration and includes:

  • Driven Element: The active radiator, typically a λ/2 dipole.

  • Reflector or Director: A passive element that alters the radiation pattern.

Two types of 2-element Yagis can exist:

  • Driven + Reflector: More common, provides modest gain with a wide beamwidth.

  • Driven + Director: Offers slightly higher gain but can be more difficult to tune.

3. Why Use a 2-Element Yagi?

While more elements can yield higher gain, a 2-element Yagi has several advantages:

  • Simple to build and tune

  • Improved forward gain (~4–5 dBi)

  • Reduced back lobe radiation

  • Compact size, ideal for portable or small-scale applications

These characteristics make the 2-element Yagi ideal for:

  • Field day amateur radio setups

  • Direction-finding (DF) antennas

  • Wireless communication experiments

4. Key Parameters in Yagi Design

When designing a 2-element Yagi antenna, you need to consider several key parameters:

Parameter Description
Frequency (MHz) Operating frequency of the antenna
Wavelength (λ) Derived from frequency (λ = c / f)
Element Lengths Physical lengths of the driven and passive elements
Spacing Distance between the driven element and the reflector or director
Impedance Matching Ensuring the antenna feeds correctly into a 50-ohm or 75-ohm system
Boom Length Total length of the boom holding the elements

5. Mathematical Formulas for a 2-Element Yagi

📏 Wavelength Calculation

λ=cf\lambda = \frac{c}{f}

  • Where:

    • λ\lambda = wavelength (in meters)

    • cc = speed of light (approximately 3 × 10⁸ m/s)

    • ff = frequency in Hz

🔧 Driven Element Length

Ldriven=λ2L_{\text{driven}} = \frac{\lambda}{2}

Or slightly less (approx. 0.47λ) due to end effects.

🔧 Reflector Length

Lreflector≈0.55λL_{\text{reflector}} \approx 0.55 \lambda

Slightly longer than the driven element.

🔧 Director Length

Ldirector≈0.45λL_{\text{director}} \approx 0.45 \lambda

Slightly shorter than the driven element.

📐 Spacing Between Elements

  • Typical spacing: 0.15λ to 0.25λ for reflector-driven

  • 0.1λ to 0.2λ for driven-director setup

6. How the 2-Element Yagi Calculator Works

A 2-Element Yagi Antenna Calculator automates the calculations based on input frequency and desired configuration. Here’s what it typically does:

  1. Accepts operating frequency (in MHz) as input.

  2. Computes wavelength (λ).

  3. Calculates element lengths based on Yagi design formulas.

  4. Provides optimal spacing between the elements.

  5. (Advanced calculators) may simulate gain, front-to-back ratio, and impedance.

Input Example:

  • Frequency: 144 MHz (2-meter band)

Output Example:

  • Wavelength (λ): 2.08 m

  • Driven Element Length: ~0.98 m

  • Reflector Length: ~1.05 m

  • Spacing: ~0.3 m

7. Step-by-Step Example: Designing a 2-Element Yagi for 144 MHz

Let’s walk through a full example.

Step 1: Determine Wavelength

λ=3×108144×106=2.08 meters\lambda = \frac{3 \times 10^8}{144 \times 10^6} = 2.08 \text{ meters}

Step 2: Driven Element Length

Ldriven=0.475×λ=0.988 metersL_{\text{driven}} = 0.475 \times \lambda = 0.988 \text{ meters}

Step 3: Reflector Length

Lreflector=0.55×λ=1.144 metersL_{\text{reflector}} = 0.55 \times \lambda = 1.144 \text{ meters}

Step 4: Element Spacing

Spacing=0.2×λ=0.416 meters\text{Spacing} = 0.2 \times \lambda = 0.416 \text{ meters}

Now you have all dimensions needed to construct a functional 2-element Yagi for the 2-meter amateur band.

8. Applications of 2-Element Yagi Antennas

Yagi antennas are used in a variety of real-world applications. A 2-element version is especially useful in:

  • Ham radio (VHF/UHF)

  • Wi-Fi (2.4 GHz directional boosting)

  • Digital TV reception

  • RFID reader antennas

  • Satellite communication (e.g., weather satellite downlink)

  • Directional jamming or detection systems

  • Emergency services and mobile command setups

9. Benefits and Limitations

✅ Benefits:

  • Simple to build, even for beginners

  • Lightweight and compact

  • Provides meaningful gain (~4–5 dBi)

  • Improves signal-to-noise ratio in one direction

❌ Limitations:

  • Less gain than multi-element Yagis

  • Narrower bandwidth than log-periodic antennas

  • Requires precise spacing and tuning for best performance

10. Top Online Yagi Antenna Calculators

If you're designing your own 2-element Yagi, here are some excellent free tools:

  1. K7MEM Yagi Calculator

  2. Yagi Calculator by VK5DJ

    • Windows application with modeling features

  3. MMANA-GAL

    • Free antenna modeling software for simulating radiation patterns

  4. Ham Radio Secrets Yagi Calculator

    • Simple HTML tool with straightforward frequency-to-length conversion

11. Final Tips and Best Practices

🧰 Building Tips:

  • Use aluminum tubing for lightweight and durable elements.

  • Mount elements on a non-conductive boom (e.g., PVC or fiberglass).

  • Ensure all connections are well-soldered or crimped to minimize loss.

🧪 Testing and Tuning:

  • Use an SWR meter or antenna analyzer to tune for lowest VSWR.

  • Adjust spacing and element lengths slightly if performance is suboptimal.

  • Test in an open area away from buildings and metal objects.

🌐 Using with a Transceiver:

  • Match impedance with a balun or gamma match to prevent mismatch losses.

  • Ensure proper grounding and lightning protection if mounting outdoors.

Conclusion: Design Smarter with a 2-Element Yagi Array Calculator

The 2-element Yagi antenna is a compact and powerful design that strikes an excellent balance between performance and simplicity. Whether you’re an amateur radio operator, a Wi-Fi hobbyist, or a field engineer, a 2-element Yagi array antenna calculator can save you time and ensure a high-performance result.

By using simple math and the right tools, anyone can build a reliable directional antenna tuned to their desired frequency. With modest effort and low cost, a 2-element Yagi can greatly enhance signal clarity, range, and overall communication quality.


read also 3 Element Yagi Calculator


2-Element Yagi Antenna Calculator

2-Element Yagi Antenna Calculator

Enter the operating frequency in MHz:

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Best Broadband Plans for Work From Home in Tokyo, Japan (2025 Guide)

With the rise of teleworking and hybrid jobs, having fast, reliable, and affordable broadband is essential—especially in a bustling city like Tokyo. Whether you're a remote worker, freelancer, digital nomad, or running a home office, this guide will help you find the best broadband plans for work from home in Tokyo, Japan in 2025.

📡 Why You Need High-Quality Broadband for Remote Work

Living in Tokyo gives you access to some of the most advanced internet infrastructure in the world, but not all plans are created equal. Here’s why choosing the right provider matters:

  • Speed: To handle video calls, large file transfers, and multiple devices.

  • Latency: Especially important for video conferencing and cloud collaboration.

  • Stability: Frequent disconnections can disrupt your workflow.

  • Support: Reliable customer service is a must when issues arise.

🏆 Top Broadband Providers in Tokyo (2025)

Here are the top broadband providers suitable for remote work in Tokyo, based on speed, reliability, coverage, and customer reviews.

1. NTT FLET’S Hikari (フレッツ光)

Overview: NTT East’s FLET’S Hikari is Japan’s most widely used fiber-optic network. Most other ISPs like So-net and OCN operate on this backbone. It offers high reliability and city-wide coverage in Tokyo.

🧾 Available Plans (via ISP partners like OCN, So-net):

  • Plan: FLET’S Hikari Next Family Type

    • Speed: Up to 1 Gbps

    • Price: ¥5,500 – ¥6,600/month (with ISP + line fee)

    • Setup Fee: Around ¥8800 – ¥22,000 (often waived in promotions)

Pros:

  • Broad coverage throughout Tokyo

  • Highly stable and fast connection

  • Can choose from many partner ISPs

Cons:

  • Complex setup (you pay for the line + ISP separately)

  • Requires Japanese language proficiency for support

2. au Hikari (KDDI)

Overview: Operated by KDDI, au Hikari is another popular fiber service, known for excellent performance in Tokyo's residential areas.

🧾 Available Plans:

  • Plan: au Hikari Home 1 Gbps

    • Speed: Up to 1 Gbps

    • Price: ~¥5,200/month (with promotions)

    • Optional ISP Bundling: @nifty, BIGLOBE, So-net

    • Discounts: Up to ¥1,100/month off for au mobile users

Pros:

  • Excellent for detached homes and family use

  • Bundling discounts with au mobile

  • High-speed and stable connection

Cons:

  • Limited coverage in certain apartment buildings

  • Requires long-term contracts for best prices

3. SoftBank Hikari

Overview: SoftBank Hikari is ideal for those using SoftBank or Y!mobile mobile phones. It runs on NTT's fiber network but includes SoftBank's own backend systems and customer support.

🧾 Plans:

  • Plan: SoftBank Hikari 1 Gbps

    • Speed: Up to 1 Gbps

    • Price: ~¥5,720/month (after discounts)

    • Mobile Set Discount: Up to ¥1,100 off/month

Pros:

  • Simple setup, good for SoftBank users

  • Good upload/download symmetry

  • Optional Wi-Fi 6 router rental

Cons:

  • Less optimal for non-SoftBank mobile users

  • Can be less reliable in crowded areas during peak hours

4. NURO Hikari (by Sony)

Overview: NURO Hikari is one of the fastest residential broadband options in Japan, offering 2 Gbps speeds. It’s ideal for power users, content creators, and tech-heavy households.

🧾 Plans:

  • Plan: NURO Hikari G2V

    • Speed: Up to 2 Gbps (download), 1 Gbps (upload)

    • Price: ~¥5,200/month

    • Contract: 2-year required for discounts

    • Setup Fee: ¥44,000 (often 100% discounted)

Pros:

  • Ultra-fast speeds

  • Flat-rate, includes ISP + line in one bill

  • Good customer satisfaction for performance

Cons:

  • Installation can take 2–4 weeks

  • Limited availability in some Tokyo apartments

5. Docomo Hikari

Overview: Powered by NTT, Docomo Hikari is a bundled internet service for Docomo mobile users. It's convenient and offers extra value through smartphone plan discounts.

🧾 Plans:

  • Plan: Docomo Hikari 1 Gbps

    • Speed: Up to 1 Gbps

    • Price: ¥5,720/month (with discounts)

    • Bundle Discount: Up to ¥1,100 off Docomo smartphone plan

Pros:

  • Convenient for Docomo users

  • Uses FLET’S Hikari backbone (stable and fast)

  • Good support channels in English

Cons:

  • Speeds and support may vary by ISP partner

  • Not a good deal unless you have a Docomo mobile

📊 Broadband Plan Comparison Chart (2025)

Provider Speed Price (approx) Contract Required Notable Features
NTT FLET’S + ISP 1 Gbps ¥5,500–¥6,600 Optional Choose from many ISPs
au Hikari 1 Gbps ~¥5,200 Yes (2-year) Mobile bundling discounts
SoftBank Hikari 1 Gbps ~¥5,720 Yes SoftBank mobile discounts
NURO Hikari 2 Gbps / 1 Gbps ~¥5,200 Yes (2-year) Very high speeds
Docomo Hikari 1 Gbps ~¥5,720 Yes Best with Docomo smartphone

🔍 How to Choose the Right Plan for Your Work-From-Home Needs

👤 Solo Remote Workers

  • Recommended: SoftBank Hikari or FLET’S with OCN/So-net

  • Why: Affordable and reliable, with good upload speeds for Zoom calls

👪 Families or Roommates

  • Recommended: au Hikari or Docomo Hikari

  • Why: Bundling discounts, stable during high use

🎥 Content Creators / Heavy Users

  • Recommended: NURO Hikari

  • Why: 2 Gbps download makes uploads, editing, and live streams seamless

🏙 Apartment Dwellers

  • Recommended: FLET’S Hikari (Mansion Type) or SoftBank Hikari

  • Why: Both are widely available in Tokyo’s apartments

🧠 FAQs: Work-From-Home Broadband in Tokyo

Q: What is the minimum speed I need for working from home?
A: At least 100 Mbps download / 30 Mbps upload. For multiple devices, aim for 300+ Mbps.

Q: Can I get an English-speaking ISP in Tokyo?
A: Some providers like SoftBank, NTT East, and Sakura Fiber offer limited English support. Consider using a service like GTN or Sakura for expats.

Q: Is installation fast in Tokyo?
A: Installation usually takes 1–3 weeks. NURO Hikari may take longer due to dual-stage installation.

Q: Are there data caps on Japanese broadband?
A: No. Most broadband plans in Japan are truly unlimited.

📍 Steps to Get Broadband Set Up in Tokyo

  1. Check Address Availability: Use the provider’s online checker with your Japanese address.

  2. Apply Online: Applications often require a Japanese phone number and sometimes a My Number card or residence card.

  3. Schedule Installation: Technicians usually visit within 2–4 weeks.

  4. Receive Equipment: Most providers ship a Wi-Fi router or ONT (Optical Network Terminal).

  5. Connect and Confirm: Ensure your upload/download speeds meet expectations.

🧾 Final Recommendation: Best Overall Plan for Remote Workers

🏆 NURO Hikari is the best all-around choice if available at your address. With 2 Gbps download speed, low pricing, and unlimited data, it's ideal for remote workers, video editors, and tech-savvy users.

For most users:

  • Best Value: au Hikari

  • Best for Expats or English Support: SoftBank Hikari

  • Most Flexible: FLET’S Hikari with So-net or OCN

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Best Broadband Plans for Home Use in Sydney – May 2025

Best Broadband Plans for Home Use in Sydney – May 2025



In Sydney, selecting the right broadband plan can be a daunting task given the plethora of options available. Whether you're working from home, streaming high-definition content, or gaming online, it's crucial to choose a plan that aligns with your usage patterns and budget. This guide explores the top broadband plans in Sydney as of May 2025, highlighting key features, pricing, and provider comparisons to help you make an informed decision.

🔍 Understanding Broadband Options in Sydney

Broadband services in Sydney are primarily delivered through the following technologies:

  • NBN (National Broadband Network): The government's initiative to provide high-speed internet across Australia. NBN plans are categorized based on speed tiers, with NBN 25, NBN 50, NBN 100, NBN 250, and NBN 1000 being the most common.

  • 5G Home Internet: A newer technology offering high-speed internet via 5G networks. Providers like TPG and Optus have introduced 5G home broadband plans in select areas.

  • Opticomm Fibre: An alternative fibre network available in certain Sydney suburbs, offering high-speed internet services.

🏆 Top Broadband Plans for Home Use in Sydney

1. Tangerine NBN 100 Plan

  • Speed: 100/20 Mbps

  • Price: AU$60.90/month for the first 6 months, then AU$85.90/month

  • Features: Unlimited data, no lock-in contract, optional home phone bundle for AU$10/month

  • Best For: Households with moderate to heavy internet usage, including streaming and online gaming.

2. Dodo NBN 100 Plan

  • Speed: 100/20 Mbps

  • Price: AU$73.90/month for the first 12 months, then AU$88.90/month

  • Features: Unlimited data, no setup fee, 30-day satisfaction guarantee

  • Best For: Budget-conscious users seeking reliable high-speed internet.

3. Swoop NBN 100 Plan

  • Speed: 100/20 Mbps

  • Price: AU$72/month (after applying code LOVE22 for AU$22 off for 6 months)

  • Features: Unlimited data, locally-based support, no congestion during peak hours

  • Best For: Users prioritizing customer support and consistent speeds during peak times.

4. Exetel NBN Superfast (NBN 250)

  • Speed: 220 Mbps typical evening speed

  • Price: AU$89/month for the first 6 months, then AU$104/month

  • Features: Unlimited data, 5 My Speed Boost Days per month, optional modem purchase for AU$170

  • Best For: Households with multiple users engaging in high-bandwidth activities like 4K streaming and online gaming.

5. TPG 5G Home Broadband Plus

  • Speed: 50 Mbps (approximate)

  • Price: AU$49.99/month for the first 6 months, then AU$59.99/month

  • Features: Unlimited data, no lock-in contract, 5G network coverage

  • Best For: Users in areas with strong 5G coverage seeking a wireless internet solution.

📊 Broadband Plan Comparison Table

Provider Plan Name Speed Price (First 6 Months) Price (Ongoing) Best For
Tangerine NBN 100 100/20 Mbps AU$60.90/month AU$85.90/month Moderate to heavy internet usage
Dodo NBN 100 100/20 Mbps AU$73.90/month AU$88.90/month Budget-conscious users
Swoop NBN 100 100/20 Mbps AU$72/month AU$72/month Consistent speeds during peak hours
Exetel NBN Superfast (250) 220 Mbps AU$89/month AU$104/month High-bandwidth households
TPG 5G Home Broadband 50 Mbps AU$49.99/month AU$59.99/month Areas with strong 5G coverage


💡 Tips for Choosing the Right Broadband Plan

  • Assess Your Usage: Determine your household's internet needs. For light browsing and social media, an NBN 25 or 50 plan may suffice. For streaming in 4K or online gaming, consider NBN 100 or higher.

  • Check Availability: Not all providers offer services in every area. Use the provider's address checker tool to confirm service availability at your location.

  • Consider Contract Terms: Some plans offer discounts for the first few months but may revert to higher prices afterward. Ensure you're comfortable with the ongoing costs.

  • Customer Support: Opt for providers with strong customer support, especially if you encounter technical issues.


📞 How to Switch Providers

Switching broadband providers in Sydney is relatively straightforward:

  1. Check Eligibility: Use the provider's address checker to confirm service availability.

  2. Compare Plans: Use comparison websites to find the best plan that suits your needs.

  3. Contact the New Provider: Once you've selected a plan, contact the new provider to initiate the switch. They will guide you through the process.

  4. Cancel Your Old Plan: After your new service is activated, cancel your old plan to avoid double billing.


🏁 Conclusion

Choosing the best broadband plan for home use in Sydney depends on your specific needs, budget, and location. The plans highlighted above offer a range of options to cater to different requirements. By assessing your usage patterns and considering the factors outlined in this guide, you can select a plan that provides reliable and high-speed internet connectivity for your household.

For more detailed comparisons and to check the latest offers, visit Finder's Broadband Comparison and WhistleOut's NBN Plans.

Note: Prices and plan details are accurate as of May 2025 and may be subject to change. Always check with the provider for the most current information.

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Capacitor Network's

 Series

CT =  1/(1/(1/C1 + 1/C2 + 1/C3))

Series
CT = (C1 * C2)/(C1 + C2)

Parallel

CT = C1 + C2 + ....CN for 2 or more capacitors

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Voltage Divider

 


Formula for Voltage Divider :

Vout = Vin * (R2/R1+R2))

Where :

R1 and R2 can be a potentiometer 

reference :

[1] Formula's, Table, and Basic Circuit, Engineer's Mini-Notebook, Radio Shack 



                                   

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