Multi‑model coverage plus real‑world performance testing! A domestically produced Bias‑T that rivals imported models—no pressure to replace them.
2026-03-06
I. Aumiwalker’s Partial Bias-T (Benchmarked against SHF and Foucs)
Currently, our company has developed the following models of Bias‑T:
Partial device showcase:
II. Definitions and Operating Principles
Bias-T (DC bias circuit) It is a three‑port passive network device, with the three ports being the RF port, the DC bias port, and the RF–DC common port (RF+DC). These three ports are typically arranged in a T‑shaped configuration, hence the name “Bias‑T,” and it can be used across all domains, from integrated circuits to test and measurement equipment and systems.
A bias‑T incorporates both a capacitor and an inductor. The capacitor blocks DC while passing AC, allowing the RF port to receive the RF signal from the DUT without conducting any DC current. Conversely, the inductor permits DC power to flow to the DUT while preventing the RF signal returning from the common terminal from interfering with the supply. This configuration ensures reliable DC power delivery to the load without compromising the integrity of the AC signal. Without such isolation, both the device’s power supply and the RF signal could be damaged. Moreover, by providing inherent voltage and current regulation, the bias‑T can partially mitigate external disturbances such as voltage fluctuations and ambient temperature variations.
III. Key Specifications of Bias-T (BT67A)
In RF circuits, the bias tee (Bias‑T) is a critical component; its performance parameters directly affect circuit functionality and even device reliability. Detailed test data clearly demonstrate the advantages of the BT67A.
1. Operating frequency range
The frequency range over which a bias‑T can operate stably—such as in satellite communications—may need to cover the Ku band (12–18 GHz). The bias‑T must be matched to the system’s RF signal frequency; operating outside this range will result in a sharp increase in signal attenuation and phase distortion. Aumiwalker offers a selection of frequency bands spanning 50 kHz to 110 GHz.
2. DC-side direct current / resistance / voltage
1). Direct current
The maximum continuous DC current that can safely pass through the DC terminal must match the operating current of the load device; exceeding this limit will cause the device to overheat and burn out. The load current should be no greater than 80% of the device’s maximum DC current (allowing for a margin to prevent overload).
2). DC Resistance
The equivalent resistance of a DC transmission line is primarily determined by the conductor resistance associated with its internal inductance. The lower the DC resistance, the smaller the power loss (P = I²R), thereby preventing insufficient supply voltage to downstream loads due to voltage drop.
3). DC voltage
The maximum DC voltage that the DC terminal can withstand ensures that the supply voltage will not cause breakdown of internal components such as the DC-blocking capacitor in the Bias-T.
4). DC pulse signal
A Bias‑T enables the supply of DC pulse signals. Its core principle relies on the frequency characteristics of its inherent inductor and capacitor, allowing DC pulses and RF signals to propagate independently along the same transmission line without interfering with each other, while ensuring that the peak current and voltage of the DC pulse remain within the Bias‑T’s maximum rated DC current and voltage limits.
3. Isolation between the RF port and the DC port
Isolation primarily quantifies the ability of an inductive coil to suppress radio‑frequency signals. The higher the isolation, the less likely RF signals are to couple into the power‑supply system; if a Bias‑T exhibits poor isolation at a given frequency, RF energy can leak into the supply network, degrading system performance. At 67 GHz, the BT67A achieves an isolation of approximately −50 dB. Consequently, when a 2‑W RF signal is injected at the RF port, only about 0.2 mW of interference will be observed at the DC port.
4. Insertion Loss
Insertion loss refers to the amount of signal attenuation between the RF port and the common port; a smaller absolute value indicates better performance. Across the entire frequency range of the BT67A, the maximum insertion loss is below 1.75 dB, demonstrating minimal signal attenuation and excellent transmission performance for low‑frequency RF signals.
5. Voltage Standing Wave Ratio (VSWR)
The voltage standing wave ratio (VSWR) is a metric used to assess impedance matching: the lower the value, the better the impedance match, and the less signal reflection and distortion. When VSWR equals 1, it indicates no signal reflection; at VSWR = 1.2, the reflection coefficient is 0.83%; and at VSWR = 1.5, the reflection coefficient is 4%.
The standing wave ratio of the BT67A varies across the entire bandwidth; in broadband applications, where the frequency range is wide, the SWR changes with frequency. Therefore, the impedance should be matched as closely as possible over a broad frequency span.
6. Group Delay
Group delay characterizes the degree of phase distortion experienced by a signal after passing through a bias‑T network. The smaller the variation in group delay, the less the signal is affected; all frequency components undergo the same time delay, and no phase distortion arises upon transmission through the system. Ideally, the group‑delay curve would be a straight line with no fluctuations. As observed on an oscilloscope, the overall group delay fluctuates within the 40–60 ps range, showing no clear monotonic trend—neither increasing nor decreasing—with frequency. These small‑amplitude variations remain within the system’s tolerance and do not compromise overall performance.
IV. Benchmarking against SHF (BT65R) and MARKI (BT-0065)
1. Relevant Indicators
2. Eye diagram comparison between BT65R and BT67A
Bias-T developed by Aumiwalker— The maximum frequency of the BT110A has reached 110 GHz. ， It can serve as a drop-in replacement for foreign SHF and MARKI products, with performance metrics that outperform industry peers. Furthermore, it has successfully passed all environmental qualification tests, meeting all specified requirements: withstand voltage for 1 hour, current exposure for 168 hours, temperature cycling between –20°C and 60°C, and vibration testing.
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Email:
sales@aumiwalker.com
Phone:
+86-10-63718360
Address:
Room 505, Floor 5, Building 6, Phase II, Nord Center, No. 1 Courtyard, Auto Museum East Road, Fengtai District, Beijing
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Contact Us
Phone: +86-10-63718360
Email: sales@aumiwalker.com
Address: Room 505, Floor 5, Building 6, Phase II, Nord Center, No. 1 Courtyard, East Auto Museum Road, Fengtai District, Beijing
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