A interdigital structure frequency doubling diode
By introducing an interdigitated frequency multiplier diode in the terahertz frequency multiplier circuit, increasing the number of dies without changing the diode length, the problem of limited power capacity of the base frequency oscillator in the terahertz range is solved, and efficient power output and low coupling loss are achieved.
Patent Information
- Application Number
- CN202210318752.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-03-29
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2042-03-29
AI Technical Summary
Making a base frequency oscillator with good power, stability and noise characteristics in the terahertz range becomes difficult, especially due to the limited power capacity of microwave semiconductor devices, resulting in a limited maximum output power of the solid-state frequency multiplier.
By introducing auxiliary tables, frequency double diodes with interdigitated finger-shaped structures are used to increase the number of dies without changing the overall length of the diodes, thereby increasing the power capacity of the device.
Without changing the diode length, the total power capacity of the diode is increased, and the coupling loss between the two signals is effectively reduced, achieving efficient power output.
Smart Images
Figure CN115295630B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of semiconductor devices, and particularly provides a finger-type structure frequency doubling diode. Background Art
[0002] Terahertz (THz) waves refer to electromagnetic waves with frequencies in the range of 0.1 - 10 THz (corresponding wavelengths of 3 mm - 30 μm). Their long wavelength band is adjacent to millimeter waves, and their short wavelength band is close to infrared rays, being in the intersection region of electronics and photonics. Compared with lower-frequency microwaves, terahertz waves have the following characteristics: 1. They utilize a wide spectral range and have a large information capacity; 2. It is easy to implement narrow-beam and high-gain antennas, thus having high resolution and good anti-interference performance; 3. They have a strong ability to penetrate plasmas; 4. They have a large Doppler frequency shift and high velocity measurement sensitivity. Therefore, terahertz waves are of great significance in communication, radar, guidance, remote sensing technology, radio astronomy, and spectroscopy.
[0003] A terahertz source with stable high-power output is the key in the application of solid-state terahertz systems; when the frequency is increased to the terahertz range, it becomes very difficult to manufacture a fundamental frequency oscillator with good power, stability, and noise characteristics; obtaining a high-frequency terahertz signal by raising a low-frequency signal through a frequency doubler is a more effective way to realize a high-frequency terahertz source. When a terahertz frequency doubler is used as a frequency source, it is required to have a certain frequency doubling efficiency and, more importantly, to maximize the output power; since realizing a solid-state frequency doubler mainly uses microwave semiconductor devices, and microwave semiconductor devices have limitations in power capacity, increasing the power capacity of the device is an effective method to increase the maximum output power of a solid-state frequency doubler. Frequency doubling diodes usually increase the power capacity of the diode by increasing the number of die, but increasing the number of die inevitably increases the length of the diode. Due to the strict limitations on the substrate width of terahertz solid-state circuits, an overly long diode cannot be applied to terahertz frequency doubling circuits. Summary of the Invention
[0004] The purpose of the present invention is to provide a finger-type structure frequency doubling diode to effectively improve the power capacity of the device; the present invention realizes a finger-type structure by introducing an auxiliary mesa, doubling the number of die inside the diode without changing the overall length of the diode, thereby improving the power capacity of the device; and it has the characteristics of low cost and easy implementation, and has good application prospects in terahertz frequency doubling circuits.
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0006] A finger-interdigitated structure frequency-doubling diode includes: N + 1 main path units, N upper side branch units and N lower side branch units. The N + 1 main path units are arranged in a straight line, and the N upper side branch units and the N lower side branch units are symmetrically arranged on both sides of the main path units. Among them, the 2nd to the N + 1st main path units adopt a double-die structure with two anodes sharing one cathode, and the N upper side branch units and the N lower side branch units both adopt a single-die structure with one anode and one cathode. The two anodes of the nth main path unit are respectively connected to the cathodes of the (n - 1)th upper side branch unit and the (n - 1)th lower side branch unit through metal fingers, and the cathode of the nth main path unit is respectively connected to the anodes of the nth upper side branch unit and the nth lower side branch unit through two metal fingers, where n = 2, 3,..., N. The 1st main path unit is used as the input, and the input signal is divided into upper and lower paths and transmitted to the anodes of the 1st upper side branch unit and the 1st lower side branch unit through metal fingers respectively, and the cathode of the N + 1st main path unit outputs the combined signal.
[0007] Further, when the finger-interdigitated structure frequency-doubling diode works, the input signal is divided into upper and lower paths, and the coupling loss between these two paths of signals is small, and the output signal is the combined signal of the upper and lower paths of signals.
[0008] The beneficial effects of the present invention are as follows:
[0009] The present invention provides a finger-interdigitated structure frequency-doubling diode, which improves the total power capacity of the diode without changing the length of the diode, and at the same time effectively reduces the coupling loss between the two paths of signals, realizing the power output of the frequency-doubling circuit based on the Schottky diode. Description of the Drawings
[0010] Figure 1 It is a schematic structural diagram of the finger-interdigitated structure frequency-doubling diode in the embodiment of the present invention.
[0011] Figure 2 It is a schematic structural diagram of the main path unit in the embodiment of the present invention.
[0012] Figure 3 It is a schematic structural diagram of the branch unit in the embodiment of the present invention.
[0013] Figure 4 It is a schematic diagram of the current and magnetic field of the finger-interdigitated structure frequency-doubling diode in the embodiment of the present invention.
[0014] Figure 5 It is a schematic diagram of the current and magnetic field of the single mesa double-die diode.
[0015] Figure 6 It is a schematic structural diagram of the terahertz frequency-doubling circuit in the varactor mode. Detailed Embodiments
[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0017] Increasing the number of die is a main method to improve the power capacity of frequency-doubling diodes. However, in a capacitive terahertz frequency-doubling circuit based on Schottky diodes as Figure 6 shown, the substrate width W decreases significantly with the increase in frequency, which limits the length of the diode. And the increase in the number of die inevitably increases the length of the diode. Obviously, an overly long diode cannot be applied to this terahertz frequency-doubling circuit. Based on this, the present invention provides an interdigital structure frequency-doubling diode, which adopts a dual-path signal structure to double the number of die on the premise of the same device length, so that the maximum output power of the frequency-doubling circuit is greatly improved.
[0018] This embodiment provides an interdigital structure frequency-doubling diode, the structure of which is as Figure 1 shown, specifically including: N + 1 main path units, N upper side branch units and N lower side branch units. The N + 1 main path units are arranged in a straight line and are sequentially marked as the 1st to the N + 1st main path units. The N upper side branch units and the N lower side branch units are symmetrically arranged on both sides of the main path units and are sequentially marked as the 1st to the Nth upper side branch units and lower side branch units. Among them, the 2nd to the N + 1st main path units adopt a dual-die structure with two anodes (Schottky contacts) sharing one cathode (Ohmic contact), and the branch units (upper side and lower side) adopt a single-die structure with one anode (Schottky contact) and one cathode (Ohmic contact). The 1st main path unit is used as the input, and the input signal is divided into upper and lower two paths and transmitted to the anodes of the 1st upper side branch unit and the 1st lower side branch unit respectively through metal fingers. The cathodes of the 1st upper side branch unit and the 1st lower side branch unit are respectively connected to the anodes of the 2nd main path unit through metal fingers. The cathode of the 2nd main path unit is respectively connected to the anodes of the 2nd upper side branch unit and the 2nd lower side branch unit through two metal fingers, and so on, until the cathodes of the Nth upper side branch unit and the Nth lower side branch unit are respectively connected to the anodes of the N + 1st main path unit through metal fingers, and the cathode of the N + 1st main path unit outputs the signal. Thus, it can be seen that in the case of the same size, the overall number of die of the diode is 4 times that of the traditional structure.
[0019] When the above-mentioned interdigital structure frequency-doubling diode works, the input signal is divided into upper and lower two paths, and the coupling loss between these two paths of signals is small, and the output signal is the combined signal of the upper and lower two paths of signals.
[0020] Further, the structure of the above-mentioned main path unit is as Figure 2 shown, two anodes are Schottky contacted to share one cathode Ohmic contact, and the two paths of signals are combined into one path at the Ohmic contact, and then divided into two paths through the upper and lower two metal fingers and connected to the anodes of the next secondary unit.
[0021] Furthermore, the structure of the above-mentioned branch units (the upper branch unit and the lower branch unit) is as Figure 3 shown, which consists of an anode Schottky contact and a cathode ohmic contact to achieve the connection between the two main units.
[0022] Furthermore, in the above-mentioned interdigital structure frequency doubling diode, the distance between the main path units is L1, the distance between the branch unit and the main path unit is L2, and the distance between the adjacent metal fingers is L3; the L1, L2, L3, as well as the sizes of the main path units and the branch units, can all be adaptively adjusted according to the specific microwave circuit according to the index requirements, and there is no need for special limitation in the present invention.
[0023] In terms of the working principle:
[0024] As Figure 4 shown, it is a schematic diagram of the current and magnetic field of the interdigital structure frequency doubling diode in the embodiment of the present invention. It can be seen from the figure that the input signal is divided into upper and lower paths, and the number of die is doubled for each path by introducing a secondary mesa. The output signal is the combined signal of the upper and lower path signals. The number of die is four times that of the traditional structure, and the total power capacity is four times that of the traditional structure. At the same time, the two path signals I 1 and I 2 from the main path unit are opposite in space, and the generated varying magnetic fields H 1 and H 2 respectively enhance the currents of I 2 and I 1 ; the two path signals I 1 and I 3 on the metal fingers connecting the branch unit and the main path unit are also opposite in space, and the generated varying magnetic fields H 1 and H 3 also respectively enhance the currents of I 3 and I 1 ; greatly reduce the overall transmission hindrance of the terahertz signal, especially the high-frequency signal in the diode; actually have better performance;
[0025] The essential difference between the current and magnetic field of the interdigital structure frequency doubling diode in the present invention above and that of the single mesa double die diode as Figure 5 shown; it can be seen from Figure 5 that the two path currents I 1 and I 2 in the two parallel metal fingers between the two mesas are in the same direction, and the generated varying magnetic fields H 1 and H 2 hinder the current of the other path, which makes the signal transmission efficiency low.
[0026] In summary, the present invention proposes an innovative interdigital structure frequency doubling diode, which doubles the overall power capacity of the diode, and thus doubles the power capacity and output power of the terahertz wave frequency doubler based on the Schottky diode.
[0027] As described above, the above is only a specific implementation manner of the present invention. Any feature disclosed in this specification, unless specifically described, can be replaced by other equivalent or similar-purpose alternative features; all the features disclosed, or all the steps in all the methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.
Claims
1. An interdigital structure frequency doubling diode, comprising: N + 1 main path units, N upper side branch units and N lower side branch units, the N + 1 main path units are arranged in a straight line, and the N upper side branch units and the N lower side branch units are symmetrically arranged on both sides of the main path units; wherein, the 2nd to the N + 1st main path units adopt a double-die structure with two anodes sharing one cathode, and the N upper side branch units and the N lower side branch units both adopt a single-die structure with one anode and one cathode; the two anodes of the nth main path unit are respectively connected to the cathodes of the (n - 1)th upper side branch unit and the (n - 1)th lower side branch unit through metal fingers, and the cathode of the nth main path unit is respectively connected to the anodes of the nth upper side branch unit and the nth lower side branch unit through two metal fingers, n = 2, 3,..., N; the 1st main path unit is used as an input, and the input signal is divided into upper and lower paths and transmitted to the anodes of the 1st upper side branch unit and the 1st lower side branch unit through metal fingers respectively, and the cathode of the N + 1st main path unit outputs a combined signal.